Science Fiction Studies

#60 = Volume 20, Part 2 = July 1993

David N.
Samuelson

Modes of Extrapolation: The Formulas of Hard
SF

[The original version of this article was written with the
assistance of a grant from California State University, Long Beach.]

John Cawelti considered the artistic claims of various kinds of formula
literature in Adventure, Mystery, Romance (1976). Distinguishing formula
from convention and chronicling development within each genre, he identified the
Western with a kind of setting, the detective story with a kind of plot, and the
best-selling social melodrama with a kind of moral view, one that supported
traditional moral values. That he failed to consider in depth another popular
genre is not too surprising. SF is distinctly formulaic, but its formulas are
multiple and various, ranging from myth to mathematics. Future battles in space
may define its film image, but few readers would limit SF to any particular
time, place, or type of action. Moreover, most books and movies called SF are
hard to distinguish from other kinds of fantasy. Always a patchwork creation,
the field of "science fiction'' has less coherence today than ever.

Like the monster Victor Frankenstein created, SF is made up of bits and
pieces of other literary traditions in various stages of life or decay. Writers
trace its heritage from myths and Märchen, "high'' fantasy and romance, travel
and adventure tales, as well as from utopias and dystopias, satires and
philosophical disquisitions, horror and ghost stories, even something as late
and variegated as Surrealism. Becoming self-aware in the '20s and '30s, the
monster lay claim to this ancestry, yet it also held itself a new thing because
of its sometime allegiance to science and technology and the rational projection
of futures. Many literary critics and scholars also find the productions from
this period on through the Golden Age unconscionably infatuated with hardware,
insufferably smug and arrogant, incomprehensibly optimistic, and barely literate
in their narrative and expository style.

Whatever apparent shape SF had in the '40s, it shifted toward politics in the
'50s and toward life styles in the '60s, perhaps never to regain a consensus
center. Expanding since mid-century to 20% or more of fiction sales, it spread
like "The Blob,'' took over its literary neighbors like "The Body Snatchers,''
and changed forms like "The Thing.'' Drawing attention to itself as if it were
the complete corpus, each innovation deformed what the body of the genre had
previously seemed to be. Each devoured form, however, refused to die, jostling
with its predecessors to claim its share of the new conglomerate being.

The quasi-Surrealist "New Wave'' of the '60s gave way in turn to feminist
counterculture quasi-utopian speculations in the 70s, followed by grungy
"cyberpunk'' visions of human-computer interfaces in the '80s. Postmodern
theorists like Larry McCafferey lay claim to all three, conflating them with
other non-realistic, counter-realistic, and self-reflexive art around the world.
Commercial publishers meanwhile continued to profit from both hard and soft SF,
using formulas of adventure, satire and social criticism, and trading on
resurgences in fantastic romance and horror stories. The latter were spurred on
by the high sales figures respectively of J.R.R. Tolkien and Stephen King,
themselves influenced by the coherence SF imposes on fantasy. Often trashy and
melodramatic, sometimes dauntingly literate and philosophically provocative, SF
does not always rely on science and technology for authority, nor is it limited
to verbal expression.

SF images and concepts have long occupied the covers of the genre magazines.
They were also part of film from its beginning, involved in the medium itself as
well as its stories. Since midcentury, however, SF has invaded pop music, tv
commercials, interactive video and computer games, and now "virtual reality.''
Saturating these markets, it reached new heights of public consciousness,
however distorted that might seem to purists. It is now popularly said not just
of atomic energy and space travel, but also of miniaturization and biogenetics,
even the end of the Cold War or apartheid, that they were once "only
science fiction.'' Today, SF embraces virtually all eccentric visions, past and
present, whatever theoretical relevance to reality traditional supporters claim.
Even the "paraliterary'' label by which critics like Samuel R. Delany
distinguish it from literature with academic credentials hardly does justice to
its protean existence.

Since SF's formal characteristics are continually in flux, the accretive
model is clearly too amorphous for a single formula to categorize. This is not
how it seemed to SF readers in the Fifties, when I was first infected.
Provincially assuming a homogeneity exploded in the next decade, most
definitions then focussed primarily on features distinguishing SF from fantasy.
These characteristics never really dominated SF writing, let alone visual or
musical media. By no means ``missing matter,'' however, even in today's SF
constellation, they are still responsible for its flavor in the universe of
fantasy. As representations of scientific values, they are especially visible
now in SF we call hard (or "hardcore'' by analogy with other addictions).

Hard SF relies on a defining characteristic of all SF, which I called in a
previous book the individual "science fiction.'' Darko Suvin's novum
achieved wider currency in criticism, as a far more inclusive term, covering
almost any change in society, psychology or science. To narrow the meaning
again, I offer the term "hypothetical'' for a model of something not yet known,
theoretically possible, but beyond historical human experience. All writers of
fiction hypothesize virtual interactions of invented entities. Like science and
engineering, however, SF makes plausible models of beings, places, and times
nobody has yet encountered. Beyond "minimal'' SF like "Flowers for Algernon,''
highlighting only a single small shift, most SF stories feature a generous
assortment of hypotheticals. Though hard SF mainly derives these through
extensions of reigning scientific theory, this is not to say that hard SF is
always scientific. Even science is not always scientific.

For science to be 100% accurate all the time is impossible, even disregarding
experimental error and interfering variables. Table salt may always divide
chemically into sodium and chlorine, water into hydrogen and oxygen, but that
was not always known and its significance has not always been understood as we
think we understand it now. The answers science provides vary with time, often
yielding progressively more accurate results. While "normal'' science, in Thomas
Kuhn's formulation, solves "puzzles,'' new ways of seeing emerge to make better
sense of the data (such as heliocentrism, genetics, and plate tectonics). Such
"paradigm-shifts'' make different questions meaningful, rendering the old
science incomplete or at least dated, sometimes simply wrong. Insofar as hard SF
ties itself to scientific findings and theory, it risks obsolescence almost as
surely as an athlete setting a new record.

In SF, however, scientific accuracy is also limited by the competing demand
for fantasy. Even hard SF requires an element of the unknown, into which writers
cast a net fashioned of reigning theory. Building on what does not yet exist,
all SF writers "cheat'' on known science, as Gregory Benford argues, calling
hard SF "a class with no examples.'' A writer who actually could apply the new
theory or build the machine would hardly settle for selling a story to a
basically low-paying market. Much SF story-telling, moreover, requires
hypotheticals defying contemporary theory: faster-than-light travel, breathable
atmospheres and edible foodstuffs on other worlds, not to mention easy
communication with alien intelligences. Without such fast answers to difficult
questions, story may turn into lecture.

SF typically ignores these impossibilities (a practice ubiquitous in films)
or conceals them with verbal legerdemain. The trick in hard SF is to minimize
cheating, not just disguise it with fancy footwork. Claiming never to invent,
Jules Verne larded his voyages extraordinaires with scientific
information as a foundation for his extrapolations. Late in his career, H.G.
Wells claimed he had allowed himself only one "impossibility'' per story. He did
not always hold to this limit, but his goal was never simply toying with
scientific ideas for their own sake. Others have rarely paid more than lip
service to this rule in its most limited form, but old SF hands call it "playing
the game'' to minimize violations of natural laws. Given a coherent fantasy,
extending science rather than simply contradicting it, descriptions of the
material universe should approximate to what is contemporaneously known to
scientific investigators.

Of all the kinds of storytelling in the SF constellation, hard SF is least
likely to be confused with other literature. The branch most closely allied to
the hard sciences, hard SF makes extensive use of machine technology and
material causation, empirical diction and relativistic morality, and the
toughness and skepticism of experimental method. It permits but does not demand
the elevation of certain literary qualities attributed to it. Robert A.
Heinlein, Tom Godwin, and Jerry Pournelle may demand macho qualities for
survival. Isaac Asimov, John Brunner, and Frederik Pohl may foreground serious
consideration of social consequences. Ideas that transcend the human condition
tend to preoccupy Greg Bear, Gregory Benford, and Arthur C. Clarke. All three
groups—which tend to overlap and do not span the entire spectrum—show a distinct
propensity for posing and solving puzzles, whether or not they propose new
paradigms.

The mixture of science and fiction that makes up SF in general and hard SF in
particular is complex and sometimes subtle. Space permits me only to sketch the
outlines. In the context of fantasy, I suggest the importance of building
bridges to relevance, one of which is extending the known. In the context of
science, I posit the importance of empiricism, determinism, and relativism.
Conditioned by these constraints, extensions in SF subdivide into extrapolation,
speculation, and transformation. Elaborating on extrapolation, hardest of the
three, I can only allude to examples of it in the literature of SF, not
demonstrating it in individual texts.

1. The Relevance of Fantasy. A latecomer to Western culture, SF can
justify its name in a sense on its mixture of old and new elements. On the one
side a late blooming avatar of fantasy, it is on the other a romantic
simplification of scientific processes. From a psychological standpoint, all
literature is founded in fantasy. Theories of the imagination identify as
fantasizing the basic situation of making in words what is absent from our
senses. "Intertextual'' theory, both literary and psychological, analyzes the
storehouse of images, conventions, and unconscious beliefs shaping both our
tales and the basis of the narrative process. Familiar vocabulary, character
types, settings, plot situations, social and sequential structures, underlie
stories we tell ourselves about history, science, art, and religion, not just
those claimed as fiction. Fairy tales and myths, the oldest extant stories,
underlie our "humanistic'' views far more than we like to admit, and color our
resistance to upstart sciences that give short shrift to such wish-fullfilment.

Overtly fantastic stories bulk large among humanity's entertainments, even in
the last three centuries of Western culture, when the demands of science and
industry tilted approved reading matter toward the practical and ostensibly
realistic. Homer and Chaucer thought nothing of using verisimilitude in tales of
wonder, but Horace Walpole had to justify the first "Gothic novel'' to
philosophes and hard-headed businessmen. However credulous audiences ever
were about myths and scriptures, epics and romances, 18th-century novelists felt
the need to claim they wrote "histories,'' not time-wasting fiction. Driven
partly underground, writers of overt fantasy became self-conscious that theirs
was not the only way to tell stories. They either had to admit their flights of
fancy were not worth the time of serious people or connect to the "real world''
as the reader conceived it on some grounds of practical relevance.

Jonathan Swift and Samuel Johnson, Montesquieu and Restif de la Bretonne tied
their allegories and satires to the workaday world by traditional methods like
extension, inversion, and exaggeration of the known, individually or in
combination. Like Don Quixote before them, Candide and Rasselas mentally extend
their educations into an unknown world as well as inverting the known. Lemuel
Gulliver meets homunculi, giants, obtuse savants, and wise horses; differences
in size and wisdom reach cosmic proportions in "Micromegas.'' Thomas More,
Tommasso Campanella, and Francis Bacon took science more seriously than Cyrano
de Bergerac, Swift, or Voltaire, but all gave it passing reference. Karl Guthke
even credits the speculations of Bertrand de Fontenelle about other inhabited
worlds with turning the tide of popular opinion toward science. Verisimilitude
was barely a consideration, given the state of scientific education. Only in the
19th century could literary tools rendering the fantastic relevant mix with
principles of scientific endeavor, allowing early (or proto-) SF to emerge.

2. Bridges to Relevance. Science, engineering, and literature make models
of worlds we imagine; some of these we convince ourselves are phenomenally real.
SF, especially hard SF, uses a number of model-making processes in creating
narrative models of the future, of alien worlds, and of anticipated artifacts
and phenomena, both alien and human. SF still uses inversion and exaggeration,
for example, although it favors extension, enlisting naturalistic details and
mimetic techniques in the service of fantasies. SF distorts realism in other
traditional ways, as well, such as satire or allegory, but the method of
distortion most characteristic of SF, and especially hard SF, is extrapolation,
a process uniting science, realism, and fantasy in highly specific ways. Shared
with and to some extent drawn from science and futurology, extrapolation is
primarily used in SF for world-building and forecasting.

The models of science, engineering, and SF are supported by three
philosophical principles (empiricism, determinism, and relativism) and two
operating procedures (prediction and control) which serve as rules for everyday
scientific activity. Empiricism, determinism, and relativism may be absolute
only in Scientism, the belief that nothing is real except what can be observed
by scientific means. On a human scale—between the atom and the star—scientists
assume them at least for the duration of the study or the experiment. These
scientific principles underlie all SF, even where the authors are not aware of
it, but hard SF writers usually take them seriously and readers expect them to.

Everything in the universe may not actually be material, divisible,
observable and measurable. Science works better with numerical precision,
however, than with vague descriptive terms. Such numbers it basically derives
from sense impressions, however much magnified by instrumentation. As
practitioners of applied science, engineers are even more materialistic, working
with physical models. Sense impressions are the stuff of fiction as well, with
subjective coloration more prominent. To make credible to its readers
experiences which can only be imagined, SF uses sense impressions, often
magnified by instruments, and often puts numbers to them as well. Thus
empiricism is a necessary if not sufficient element of both science and SF.

Sometimes in subnuclear physics, an effect may precede its apparent cause.
Thus science itself seems to disprove absolute determinism on the
subatomic level, from which all others are constructed in a material or
empirical model of the universe. Outside physics as well, scientists have taken
to speaking of probability more than causation, modifying the causal principle
more than abandoning it. All thought and expression may not need linearity, but
"natural language'' can not manage without it. Modernist and postmodern
story-telling techniques fragment plot and question causation, suggesting that
linearity is outmoded in fiction, but readers routinely reorder a complicated
narrative structure as if a linear causal sequence predated the complication. If
causality itself is outmoded, clinging to it probably reveals a limitation of
the human mind. Richard Feynman argued that nobody can visualize the situation
in an atomic nucleus; it's questionable how many people can visualize an
indeterminate universe at human scale.

The most recent of the underlying principles to emerge, relativism is
also quite exacting. It assumes that scientific findings are valid only in
limited context, "relative to'' an observer, as well as to a measure we
operationally call stable. What can be found in the lab may not exist outside
it. Whether Sol circles Terra or vice-versa is less a matter of correctness than
identification of an observer's physical frame of reference. Today's "correct''
position, that neither body provides a fixed center, eliminates an absolute
frame of reference. Physicists don't know the fixed center of the Universe, if
there is one, or if there is only one Universe. Compensating for past errors of
anthropocentrism, we undoubtedly substitute new ones; we can hardly avoid a
human viewpoint and a biased interest in what we investigate. Yet scientific
discoveries have decentered past biases, transcended earlier frameworks focussed
on more limited experience and conceptualizations, each step forward making us
progressively less provincial. Relativism suggests the inevitability of such
self-correction, if our frame of reference continues to expand.

Intellectually, engineers have an easier time of it; their real world
assignments have less tolerance or "wiggle room.'' They can isolate a part of a
system, as a "Black Box,'' disregarding what goes on inside it, concentrating on
input, output, and ``throughput.'' Fiction writers cannot fully understand or
describe all the behavior of their characters, let alone the world they inhabit.
In a given context, they may also assume a moral relativism, measuring values by
a standard not officially approved in the world in which they live. Hard SF
writers echo the work of scientists, engineers, and fiction writers in general.
They contextualize their stories in space and time, they avoid detailed
description of a conception or invention that does not exist, and they measure
characters' values against a world view at least partly scientific in origin.

Even more pragmatic than the axioms discussed above are two deterministic
operating procedures, prediction and control. Some scientists
discount prediction, but most accept that verification of theories, inside and
outside the laboratory, depends on part of the material universe behaving as
theory says it should. To test that prediction, they control the experimental
situation.

Scientists try to control the subject under study as much as possible,
eliminating variables, making verification of a prediction less ambiguous. Least
able of scientists to control objects of their study, even astronomers rejoiced
in 1988 when a Supernova visible in the Southern hemisphere fulfilled most of
their expectations. Like other hard scientists, they assume the virtual
interchangeability of matter in a given state; nature is the control mechanism.
Laboratory scientists, however, need to minimize contamination by chance or
factors other than what is isolated for study. The soft sciences need "control
groups,'' which they maintain and observe, to guard against the possibility that
the hypothesized effect might occur even without the variations introduced for
the experimental subjects.

Scientists try to establish measures of consistency and coherence internally,
not just with the world of phenomena. Internal coherence means avoiding
self-contradiction. "Mature'' sciences require self-consistent tenets, although
specific findings constantly subject them to challenges for revision.

Internal consistency is usually valued in literature as well. As Rabkin
points out in The Fantastic in Literature, wherever we locate a text on a
continuum between extremes of pure realism and pure fantasy, we expect the game
to have rules. Even books that seem to deny coherence are consistent in their
denial, like Tristram Shandy, the "Alice'' books of Lewis Carroll, and
David Lindsay's science fantasy novel, A Voyage to Arcturus.

Literary texts also follow conventions or codes marking them as literary,
codes that create and exploit reader expectations. These codes are both
internally and externally imposed. Jonathan Culler points to wholeness,
continuity, and adherence to rules of grammar and punctuation as relevant to
most texts, though some literary writers flout these rules to call attention to
them. At a more self-conscious level, long-standing narrative conventions of
myth and fantasy influence most if not all modes of story-telling. In fantasy,
which rarely claims to represent phenomenal reality, many of these conventions
are also metaphysical markers, establishing human relations with the
supernatural.

Even fairy tales and quest romances, however, are consistent with external
standards imposed in their times. They assume certain givens about the behavior
of powers of good and evil, of royal or heroic personages, even of ordinary
people. Based more on metaphysical than material causes, their simplistic
conceptions of human psychology are still relevant to human experience. In more
mimetic literary forms, such codes are still present, but they must vie with
others standing for empirical experience and our theoretical processing of it.
In Anatomy of Criticism and elsewhere, Frye calls myths "displaced'' in
mimetic literature, but displaced how far? Humanistic values rooted in
mythological thinking will seem natural to people if longevity and cultural
inertia have embedded them in cultural consciousness.

External standards apply in all literature, including SF. Stories reflecting
contemporary life are "historical'' in a sense, but the research involved is
contemporaneous with the writing. Contemporary readers evaluate the credibility
of narrative situations and events, taking for granted the same social codes and
literary conventions. A story set even a generation in the past requires more
research, if it is to reflect accurately the memories of readers. Since fewer
readers are well-versed in more distant times or climes, we evaluate credibility
in the distance by a mixture of criteria. Some are simple transpositions of
present habits and mores, but educated readers also expect consistency with the
historical record. A fictional attempt to kill Winston Churchill must not
succeed in this timeline, if the story is to be regarded as realistic.

Like other writers, SF writers use measures of external consistency. They
report concrete details to enlist the reader's senses on their side, and to let
readers compare their images of reality with the phenomenal world they know.
More so than other writers, however, they rely on theory to establish imagined
reality. Historically, such reliance is not unique. One thinks of the
"elements'' of Earth, Air, Fire, and Water; the psychology of "Humours''; Social
Darwinism; the scientific ``religions'' of Marxism and Freudianism; even the
recent attacks by Michel Foucault on the post-Enlightenment invocation of
``disciplines'' that have rationalized society's spreading control over health,
crime, and sex.

Three things are new about the reliance on theory in SF, however. SF is
oriented toward examining possible changes, not just maintaining the status quo.
Beginning with physics, itself philosophically undermined by uncertainty, SF
works outward into less predictable territory, including widely acknowledged
pseudo-sciences. Finally, SF is both intellectually and aesthetically distanced
from the theories it depends on. SF writers openly treat as hypothetical most
aspects of the place, time, events, and characters they create. The fictional
world of the "realistic'' is geared more toward facts, the world of the
``fantastic'' toward desire, both positive and negative aspects. SF seeks to
occupy a fictional universe in the middle ground, toward which it constructs
conceptual bridges, extending what we think we know into what we know we don't.

3. Extension Bridges. Regardless of its setting in time and space, SF
depends on transgressions of what its readers think of as reality. To justify
those transgressions, it establishes images of reality on grounds essentially
theoretical. Extending scientific laws or facts into the unknown, SF treats what
could be in theory but can not be verified in fact. This "scientific'' thinking
connects the phenomenal present (and sometimes the past) with an imagined future
(sometimes an imagined present or past). These connections typically cross three
theoretical bridges: extrapolation, speculation, and transformation.

Depending mainly on what is verifiable, or at least that which is consistent
with what is thought to be known, hard SF predominantly bridges the gap with
extrapolation, extending trends or tendencies from one time frame (or domain
of knowledge) into another. SF writers commonly use extrapolative techniques for
building environments and ecospheres; they are more problematic when applied to
cultural history. The open-ended phrase, "If this goes on . . . ,'' often
associated with negative or cautionary tales, sums up the neutral essence of
extrapolation.

Less bound to the knowable and more congenial to fertile imaginings, soft SF
depends on more flexible techniques, labelled speculation. Congenial to
philosophy, fantasy, even realistic fiction, speculation can have a special
relevance to hard SF as inverted extrapolation, working out theoretical ways
something imagined for other reasons might be judged possible. Speculation may
flow from premises, ideas, even metaphors not based in science, but many SF
writers feel an obligation to rationalize even outrageous speculations after the
fact. Linking speculation to fantasy and philosophy, another open-ended phrase,
"What if?,'' sums up its essence.

Some extrapolations from "hard science'' data or theories can lead to
fictional worlds or world-views we can hardly recognize as emerging from modern
society, however heavily influenced it may be by science and technology.
Although grounded in science, such transformations cast doubt on basic
categories of knowledge and thought, including science itself. We can see
examples of these in the recent past. A conceptual revolution or series of
revolutions in physics near the start of this century has had far-reaching
influence. A revolution in geology near mid-century greatly altered our view of
the crust of the earth. Such paradigm-shifts have also happened recently or are
happening now in biology, brain science, and linguistics.

Far more often than in science, which is basically skeptical and
conservative, SF "thought-experiments'' invoke far-reaching paradigm-shifts.
Rarely do they test these for internal consistency beyond the scope of the
story, let alone external consequences for science or the universe. Beyond such
staples as travel in time and beyond light-speed, popular paradigm-shifts have
included A. E. Van Vogt's "Null-A'' universe and William Gibson's "cyberspace.''
Some conclusions these changes lead to are incompatible not only with old
scientific paradigms but also with the conventions of narrative fiction.

Absolute empiricism denies the existence of a soul, perhaps even of aesthetic
experience, contradicting long-lived views of human sensibility. Absolute
determinism, while allowing for chance, threatens to turn characters into
puppets, denying traditional concepts of free will and human dignity. Absolute
relativism makes every event unique and its experience contingent on shared
reference grids; it casts doubt on most standards of behavior. The
quantum-relativity transformation in physics not only introduces uncertainty on
a subnuclear level; it also makes time and space contingent categories. Given
multiple lines of reality (alternate time-lines or universes), the reading
experience tends to degenerate into fantasy or selfmockery, neither of which
invites belief.

Paradigmatic transformations may increase the impact of scientific principles
on causal perception or introduce previously unknown areas of reality, from the
mind to the universe (or universes). They may restore intuition to scientific
enterprises, as Benford notes in physics. According to Fritjof Capra and Gary
Zukav, however, intuition is just one parallel between physics and Eastern
mysticism; implicit in their discussions is the sense that these parallels
restore the value of old religions. Less rooted in science, the route from
speculation to transformation may be less paradoxical, but no less disruptive.

Each of these bridges requires extended discussion, but space permits only
the first to receive it here. Long as it is, the following analysis is
suggestive rather than exhaustive; exploring every angle of extrapolation would
take a book. SF examples are cited where possible, but none are subjected to
close examination at this point. Discussion centers on identifying guiding
principles of extrapolation, as well as its application in building alien worlds
and constructing plausible futures.

4. Principles of Extrapolation. The bridge of extrapolation is familiar
enough in SF that it became the name of the first academic journal devoted to
critical and scholarly writing in the field. SF's use of extrapolation, however,
is more extensive, complicated and subtle than its use as a catch-phrase might
suggest. Simply put, extrapolation extends a series of numbers in logical order.
Given 1 2 3, the next numbers for counting are 4 5 6. In the series 1 2 4 7 11,
each enlarged by one more than the one before, the continuation is 16 22 29.
Similarly, 1 4 9 16—all squares—lead to 36 49 64. Extending the principle of
increase past a known end-point, all extrapolation stems from an exercise in
mathematical logic.

Scientists and SF writers apply this logical principle to the real world.
They extrapolate from the known into the unknown when they try to imagine
conditions not observed in detail, based on similarities and continuity with
what we think we know. What we have not directly observed, of course, includes a
vast amount of territory. It comprises unexplored areas of the earth and the
vast expanses of the universe beyond Earth, including the worlds of our solar
system. Also beyond our observation are the future, the distant past, and most
of the Microverse, the domain of the microscopically small: cells, molecules,
atoms, and beyond.

SF's extrapolative practices build on the same sciences, but
"world-building'' and "forecasting'' use different methods. World-building
extends scientific processes; forecasting extends historical processes. Whenever
intelligent manipulation of the material universe is involved, they overlap
significantly.

Building alien worlds gives SF writers a chance to exercise their scientific
ingenuity. The task is to construct environments alien to Earth which are still
natural, consistent with what science knows about nature on this world and
assumes about its continuity throughout the material universe. The writing
itself is a product of human imagination, conditioned by language and history,
but the builder of an alien world in fiction starts from scratch in a sense,
treating it as untrammelled by human history. Ostensibly, this world may exist
at any time since the Big Bang, even before or after the present dispensation,
without regard for human history or biological scale. Olaf Stapledon's Star
Maker is the outstanding example of such cosmic reach, but Poul Anderson's
Tau Zero, James Blish's The Triumph of Time, and George
Zebrowski's Macrolife also try to envision the end of our universe, if
not its beginning.

In theory, the whole universe is the author's laboratory to experiment in
with verbal models of matter and energy. Considerations of relevance and
accessibility, however, tend to keep the creation within reach of modern times.
The scope of understanding and sympathy of readers with minimal scientific
education is limited. The theoretical operating constraints are the "laws of
nature,'' conceptions or constructions about which scientists have achieved
consensus at a given time. In this respect, writers of hard SF seek to be
stringent, limiting themselves to what can be extrapolated directly from known
science.

For the duration of the story, scientific conceptions are generally assumed
to be timeless and universal. Taken to apply more or less uniformly throughout
the universe, the laws of physics, for example, may be extended at will in space
or on other bodies of matter (asteroids, satellites, planets, stars, galaxies,
nebulae, etc.). Puzzle stories set within the solar system take for granted
familiarity with such laws; for more distant climes, the author specifies the
conditions early on. Many SF writers have written such stories, including
Anderson, Benford, Clarke, Clement, Forward, Niven, and Sheffield.

Unlike the distant play of building alien worlds, forecasting is clearly
relevant to contemporary concerns. Not a science in any serious sense, it is a
combination of soft sciences that can be treated in fiction as if it had
scientific rigor, like "psychohistory'' in Asimov's
FOUNDATION narratives. In such
exercises, writers extrapolate trends from a given historical base to arrive at
a future. Forecasters may start from any time, future or past; usually choosing
the 20th or early 21st century, they opt even more than world-builders for
humanly comprehensible time lines.

The laboratory in this case is usually human civilization, i.e., its Western,
technological variety, mostly on Earth or in its presumed expansion into space.
Both hard and soft sciences set theoretical limits to forecasting, based on
dominant ideas of what is susceptible to rigorous testing about human structures
and conditions. Like the world-builder, the forecaster assumes a universe
responsive to empirical, deterministic, and relativistic questions, but other
assumptions separate the two methods. Barring a global catastrophe, forecasters
assume a human future in which science and technology evolve and progress in an
all but autonomous manner. They also typically permit intelligent beings to
behave in ways not wholly predictable.

According to the first assumption, continuity and progress operate in science
and technology as in no other area of human knowledge. Thus, the starting point
of a given extrapolation may be further advanced than anything known by science
at the time of the writing. Other dimensions of human experience are treated as
even more variable, though authors try to extrapolate them as well, usually from
a scientific or quasi-scientific base. Such a narrative may treat the social
sciences as if they had empirical certainty, or were ideologically dependent
upon harder science and technology. Alternatively, areas of human life less
accessible to scientific analysis may be treated more as speculation than
extrapolation, giving writers wide latitude.

Time factors are an important consideration. Some futurologists divide
forecasts into near-future (15 years), mid-future (15-50 years), and far-future
(over 50 years). This division implies a hierarchy of certainty, though few
futurologists of standing would declare any projection certain. Extrapolations
in SF also include longer time-spans, but they have their own constraints as
well. Distance in time decreases the degree of certainty in one's
extrapolations, leading back to world-building in the past, onward to
speculation in the future.

In futurological usage, near-future projections are more plausible, though
they can prove wildly errant if important elements are overlooked or
under-valued. In SF, moreover, near futures usually lean heavily on
technological and social forecasts, often with gloomy outcomes. Far-future
projections are typically more speculative and more imaginative, less bound by
contemporary obstacles past which we can not see our way. More distant futures
often reflect more of our hopes and wishes, invoking the psychological sense of
"projection.''

The severest form of extrapolation in forecasting concerns only one
technological or social variable. The results of such an exercise may be wildly
out of step with conceivable reality. At one time, for example, the U.S. Defense
budget was increasing faster than the Gross National Product; a comparable
argument today is made about health care costs. Such straight- line
extrapolations show the impossible: a part becoming greater than the whole.
Pohl, C.M. Kornbluth, and Robert Sheckley have imagined such states of affairs
for satire, rather than for mimetic effect. Unmodified straight-line
extrapolations are rare in fiction and futurology; both disciplines are more
sophisticated than that, and allow many kinds of complications.

Futurologists have developed more precise terminology than SF writers,
overtly routinizing many activities of their discipline. Used in computer models
for highly complicated extrapolations, as well as in more intuitive studies,
their terms place in broad relief similar procedures used in SF. The most
important are probably "cross-impact studies,'' "second-order consequences,''
"wild cards,'' and "scenarios.''

Cross-impact studies bring into analysis factors which conflict with the
continuation of an individual trend. Among them are limited resources, competing
trends, and social intervention. A classic example is the vision-phone, a
long-time expectation of electronic engineers as well as SF writers. Technology
exists for widespread use of visual telephones; booths have been available for
years for conference calls and electronics firms still try to market sets for
the home. In television advertising, some companies still project routine home
use for this technology. Consumer interest in the product, however, has always
been limited. Cost, convenience, privacy, and the increasing availability of
alternate means (faxes, electronic mail, computer bulletin boards) help keep
large-scale spread of this product in the realm of SF.

Damping effects are another cross-impact. Actions may have consequences that
radically change the conditions underlying the original extrapolation. In both
physical and social environments, trends cancel themselves out, cyclically or
irreversibly. Ecologically, population growth is always checked in some way.
When deer overgraze their feedlands or predators their prey, they die back until
there's more food per animal. History records many checks on human population,
too: plagues, famines and infant mortality we share with most other animals, war
with only a few. Less obviously deterministic, damping effects also affect human
groupings (tribes, nations, etc.), which oscillate between such extremes as
cut-throat competition and cradle-to-grave security.

Quantitative change leads to qualitative change, in both environmental and
socio-historical frames of reference. Most life on Earth is utterly dependent on
the planet's oxygen-rich atmosphere, originally produced by one-celled animals
that made the earth unlivable for their own kind. If it is not checked, human
pollution of the atmosphere with the residue of fossil fuels and
chlorofluorocarbons could make the earth just as uninhabitable for us. Stephen
Jay Gould in Wonderful Life shows the natural history of Earth replete
with examples of species that died out for many reasons; the most impressive of
course were the dinosaurs that ruled the planet for 150 million years. There is
no scientific reason to exempt human beings from extinction.

In the 1960s, Alvin Toffler coined the term "future shock'' to describe the
qualitative psychological effect on modern human populations of continual,
increasing, and apparently irreversible change, citing numerous cases in
20th-century history. The findings of archaeology and physical anthropology
suggest similar effects during the Neolithic Revolution, when humans invented
agriculture, domesticated animals, built cities, and founded other enduring
institutions. A long time on the scale of a single human life, the 10,000 years
between then and now is barely a blip in the lifetime of the planet.

Following the axioms and assumptions identified earlier, straight-line
extrapolation and first and second-order complications are roughly calculable in
a temporal context, but few futurologists or SF writers settle for simplistic
determinism. Too many events have taken experts by surprise, even after the
tools of scientific forecasting were developed. Participants in both disciplines
develop "scenarios'' introducing indeterminacy, a term borrowed from physics.

The object of study in any field of science usually reveals emergent
properties impossible to predict from a constituent science. Chemistry is a
constituent of biology, which must be consistent with its laws, but neither the
voluntary activity and life cycles of biology emerge inevitably from laws of
chemistry. Similarly, while rapid changes of state in chemistry are consistent
with physical laws, they can not be predicted from those laws. At the subatomic
level, even physicists are limited in what they can know or predict, in keeping
with the "principle of uncertainty'' associated with Werner Heisenberg.

The indeterminacy factor in behavior stems partly from the impossibility of
knowing enough details about the system under study, but also from the
willfulness of intelligent beings as objects of study. The classic example of
the resistant subject produced the "Hawthorne Effect,'' named for a study of
employee-management relations in a Western Electric manufacturing plant in
Chicago. This study found a rise in efficiency when management increased the
lighting—as it did when the lighting was reduced. Knowing they were being
studied, workers were concerned to make a good impression or fearful of making a
bad one.

Principles of indeterminacy are extended into otherwise sober technological
forecasting, as various surveys have shown (cf. Arthur C. Clarke's Profiles
of the Future). Experts literally guess when—not if—hydrogen fusion or
anti-gravity will be developed. Strictly outside anyone's expertise, these
breakthroughs are still considered possible. Other wild cards are at the
breaking point of speculation. Contact with extraterrestrial intelligence and
control of extra-sensory-perception may seem on the edge of possibility. Others
are clearly past the edge of present conceptions of physical law, e.g.,
invisibility and miniaturization of biological entities, reversible time travel,
faster-than-light speed, and two-way communication with the dead. Such questions
subject even experts to psychological projection. From a science-fictional
viewpoint, however, once we impose our hopes and fears and desires on an
unpredictable future, extrapolation can work from that situation, assuming a
predictable state of human society and human technology from the point of
impact.

All three kinds of complications may be invoked in terms of the "Gaia
Effect,'' James Lovelock's theory that the planet Earth itself maintains a
relatively stable climate. Physical scientists are understandably skeptical of
this hypothesis, but some have sought material ways to proved or disprove it.
Insufficient data, inadequate computer modelling, and highly questionable
interpretation yield indeterminate results to date. Neither known nor disproved,
illustrating emergent properties, social expectations, and psychological
projection, the subject of a living planet maintaining its balance may seem a
natural for SF. Writers who have imagined planet-wide beings have included Le
Guin, Lem, and Stapledon, but the dramatic potential is limited, as for a hero
with no known weaknesses.

5. Extrapolating Scientific Processes. Centered in the physical sciences,
world-building should be the more reliable of the two methods of extrapolation
SF commonly uses. It even underlies forecasting, supplying the ground rules, but
its immediate relevance is less obvious. We take for granted that our world
exists as it is; we are bred to be well suited to it. Imagining other worlds, SF
writers are not so complacent; all aspects of world-creation are in play.
Playing the game seriously, hard SF writers must construct a setting, an
environment, usually a culture with a history, all of them differing from ours,
yet consistent with present-day scientific knowledge.

The general principles of world-building are fairly simple, based on what
hard evidence we have. That limited evidence depends on long-term and
large-scale, but not exhaustive, explorations of one watery planet, a few trips
to its satellite, and a few dozen instrumental probes of its rocky and gaseous
neighbors. What science has won, however, by hard-fought analysis with many
missteps, SF reconstructs by relatively easy synthesis with no assurances about
accuracy.

In building a fictional world, writers who do not simply assume an
"earthlike'' planet are obliged to work within existing constraints of
cosmology, planetary science, and biochemistry. Hard SF writers rarely question
the consensus cosmology of physicists concerning the formation of planets or the
assumptions of biologists concerning the material causes for life. Fictional
extrapolations differentiate themselves from the hard sciences largely in terms
of considering potential alternatives not yet found. In imagining an alien
world's inhabitants, writers have more freedom. If they do not simply allegorize
or satirize human history, however, they must rely for plausibility on
extrapolation from the social and behavioral sciences treated more or less
deterministically. The greatest weakness in Hal Clement's classic of
world-creation, Mission of Gravity, is the characterization of its
aliens. They look like centipedes with lobster claws, act and think like
Renaissance sailors, and talk largely like '50s engineers, at least as they are
represented in American SF.

For anyone studying nature, two conflicting principles seem to govern
material bodies in the universe we know. According to the Second Law of
Thermodynamics, entropy increases. Energy levels even out over time, ultimately
eliminating variations so that everything is a kind of low-temperature soup. In
contrast to this great equalizer, Louise Young argues in The Unfinished
Universe that the history of the universe so far shows energy
differentiating itself into various states and shapes. The energy state we call
matter extends and varies itself enormously, even before reaching the levels of
life and culture. At each next level of complexity, the differentiating process
rises to a higher mathematical power. The tension between entropy and
differentiation allows writers considerable imaginative play.

Consensus cosmology among physicists holds that some 15 billion years ago,
all the energy in our universe exploded from a single point in a Big Bang,
unfolding in a lumpy, differentiated state ever since. Nebulae begat stars which
begat planets; at least one of these begat life, which in turn begat culture.
Assigning stars to nine letter classifications, largely based on temperature, we
treat novas, supernovas, neutron stars, and black holes as special cases. Given
fewer known examples, we classify the debris circling Sol as planets, satellites
(including rings), asteroids, and comets. Distinguishing between gas giants and
balls of rock, we find several variations in this system. While everything may
even out in the end, matter and energy seem multifarious; this apparent decrease
in entropy the Second Law permits in a "local'' situation.

On the biological level, we chart the development of life from simple
proteins to DNA and RNA, from one-celled beings to colonies of similar but
somewhat differentiated cells to creatures like ourselves with multiple organs
consisting of specialized kinds of cells. Each level may include numbers of
symbiotic relationships on internal and external levels, culminating (in our
anthropocentric interpretation) with our vaunted intelligence, which we
typically deny or denigrate in other species. In terms of the variety we know
has existed, differentiation seems to be winning, but more species have died out
than are now alive, and the number of those alive today is dwindling.

Viewed anthropologically, not as a possession of polite people, culture is a
set of value distinctions shared by a group of humans. Whether or not there are
empirical reasons for such distinctions, their major social function is to
differentiate the group from gross physical matter, other animals, and other
people. The origins of such values are buried in contemporary consciousness,
where they form the assumptions and emotional bases of logic, aesthetics, and
other cultural values. The most deeply held of these are typically the
"numinous,'' the supernatural element of values we call religious. The most
arbitrary values of all, their material basis consists of shared values about
the unknown (e.g., contact with divinity, the origin of life, the existence of
the "soul,'' and survival after death).

Each group's distinguishing set of values inevitably changes over time,
however much effort is spent on trying to preserve it. While it is in place,
moreover, people are willing to shed their own blood over it, as well as the
blood of others with whom they differ. Here, too, entropy conflicts with
differentiation. Each culture may be arbitrary, but that arbitrariness is
precisely what distinguishes it from other cultures. People centered in
technology may think technology decreases differences along with distances
between cultures, another staple SF assumption, but we wear ethnocentric
glasses. Other cultures become more alike to the extent that they buy into our
technological way of life, but even then they typically maintain "spiritual''
differences, arbitrary to a materialist's eye. Both decreasing and increasing
material discrepancies may exacerbate spiritual differences.

For building a hypothetical world—and even the bodies of our solar system are
partly hypothetical objects to us—physics sets the paradigm for other sciences.
The most successful at prediction, control, and reduction to mathematics, it
deals with the simplest levels of matter and energy, from which the objects of
other sciences are constructed. Relativity and quantum mechanics must be
admitted, but most spectators follow a paradigm constructed from physics as
practiced and formulated in the 19th century and before. For operations above
the subnuclear level and below the cosmic, the old physics works fine, perhaps
especially in fiction. Oversimplified, this paradigm is analytical, mechanistic,
and systematic, but not infallible.

The physics paradigm involves both analysis and synthesis. Analyzing an
object of study into its smallest constituent parts, physicists build mental
models out of their perceived interactions to suggest an understanding of the
whole. Subnuclear particles and operations have been known for nearly a century,
but "atomic'' and ``elemental'' are still useful terms for the smallest part of
something that can stand alone.

For purposes of modeling a world, we generally regard laws ascribed to
science as mechanistic, describing processes virtually inexorable once they
start. These laws must be consistent in their application and part of a coherent
system, not contradicting either rigorous observations or laws in that science
or another. Physics constrains the other sciences, but this system of checks and
balances also works in reverse. If a more complex science demonstrates something
contrary to the assumed limitations of a simpler one, those assumptions must be
adjusted.

This procedure does not simply operate like clockwork. All scientific
explanations are partial, allowing the model-builder a certain amount of
latitude, especially vital to a fiction writer. Two obvious limits to rigid
determinism are those of perceptual indeterminacy and conscious intervention.
Principles of indeterminacy arise partly out of physics, partly out of
differences between the sciences, and partly out of the mathematical language
sciences use to describe things and events.

At the subnuclear level, the impossibility of absolute knowledge is
symbolized by Heisenberg's Uncertainty Principle. The position and velocity of a
particle cannot be known at the same time, whether this be considered a failure
of tools or concepts. Uncertainty is not limited to subnuclear conditions,
however. It is impossible in any science to demonstrate perfect continuity of
nature with laboratory conditions. The loopholes involved may be infinitesimal
and it is risky to try to enlarge them, but change at the microcosmic level
makes itself felt on our scale of the world. Like a nail in a horseshoe losing a
battle, a wayward subatomic particle can affect the germ plasm or the synapses
of a brain, resulting in the death of a person, a species, a planet.

Indeterminacy is also apparent in relationships between the sciences.
Chemistry may not violate laws of physics, but physics cannot predict everything
in chemistry. Biology has a similar relationship to chemistry. Changing the
scale of study reveals unpredictable properties of matter and energy at the next
higher level of complexity. Heat makes life possible on Earth, but life without
access to sunlight, as at deep ocean heat vents, was not predicted by physics
and chemistry, and the forms such life takes were not anticipated even in
biology. Ascending the ladder of complexity takes us from physics to chemistry
to biology to psychology to sociology, with stops in between (biochemistry) and
to the side (biophysics, psychophysics, psychochemistry). In the simplest
analysis, more complex fields just have more variables than the sciences that
underpin them.

Gödel's Theorem underpins with mathematical certainty these practical
uncertainties, establishing that no closed system can determine all of its
contents. The theorem is strictly mathematical in scope, but the extent to which
the sciences are mathematically coherent restricts them as well. Again the
model-builder is freed to imagine something of which we have no experience, if
it is consistent with the known.

SF involves literary as well as scientific models, but the fictional
construction of worlds depends on a mixture of the sciences. Hard sciences
directly impact on the soft, but social and behavioral factors usually drive
activities of both science and engineering. Whatever we regard as natural,
intelligent intervention leads to "artificial'' variations in evolutionary
development or variations of technology, which includes not just artifacts and
machines but also laboratory and social processes in chemistry, biology,
language, and culture. Potential in every fictional world, this principle is
inherent in SF creation.

6. Hard Sciences. For the astronomical situation and the composition of
an alien world, the physical sciences are obviously primary. They cannot be
taken for granted, as in mundane fiction or SF set on an "Earthlike planet.''
Cosmology is invoked for the astronomical situation and composition of an alien
planet, and for anomalies in the Earth's situation (solar or planetary
variations).

The history of a star's formation, as well as its specific size, color, and
temperature, impacts on its possessing inhabitable worlds. Nurtured by a G-type
star of nondescript size and temperature, we are suspicious of stars near the
ends of the spectrum, like blue giants and red dwarves. Although neutron stars
appear in several SF stories, only Robert Forward in Dragon's Egg has
ever described characters inhabiting one. Black holes are so exotic, even SF
finds them stella incognita. This does not prevent their being used as a
Black Box of sorts: Anderson, Benford, Niven, Pohl and others have written about
human encounters with them.

Compared to stars, planets are so small and dark that their very existence
outside our solar system has never been conclusively demonstrated. To present
telescopes, a slightly perturbed stellar orbit would demonstrate at best the
existence of a very large world, possibly indistinguishable at this distance
from a neutron star or a black hole. SF draws its planetary models from our
solar system, possibly unrepresentative, and from guesswork about effects of
different kinds of stars on their own families of planets. Based on what we know
of our solar system, a young planet might be quite volcanic and subject to heavy
bombardments of solid matter. We would not think that a good candidate for
harboring intelligent native life. Its formative eons would also determine its
radioactivity and atmosphere; a world too close to its primary may have too
little of the former and none of the latter. Deposits of minerals can also be
guesstimated from planetary size, astronomical situation, and historical
formation.

Otherwise, what matters most for a fictional setting are a planet's distance
from its primary, its rotation, inclination to the ecliptic, mass, and any
satellites it may have. These determine its revolution, day, seasons if any,
gravitational pull, and tides, respectively. The existence of satellites may
also interest intelligent species in exploring space.

The world that emerges has specific mineral and atmospheric elements, as well
as a distinctive geography and topography. For each of these today we have a
"mature'' science, although extending terms like geology and geography is
provincial, since they derive from "geo'' or Gaia. In such sciences, we think we
can extrapolate the behavior of physical elements and structures under
foreseeable circumstances. Scientific assumptions based on a single planet may
be inappropriate for other worlds, however. Planetary scientists' predictions
often went awry when the Voyager probes beamed electronic impulses back to us as
they passed other bodies in our own solar system. Landings on Mars and the
mapping of Venus also yielded surprises.

Physical science includes more than inert matter, however distinctively it is
composed or disposed. Natural processes take place on worlds and in suns unaided
by life forms. In our Earthly experience, matter changes state, depending on
temperature, air pressure, and other factors. In solid, liquid, or gaseous
forms, it may combine with other matter. If its atomic structure is unstable, it
decays radioactively. Chemical changes also take place without intelligent
intervention, but science and engineering can speed or slow changes and
introduce others not exploited by nature, if the potential is there.

At some point, life may emerge, in ways distinctive to the planet's
biochemistry. Animate matter is subject to gravity and climate, length of day
and seasons, and chemical constraints and incentives, such as fuel consumption,
oxidation, and excretion of waste products. A constraint SF often overlooks or
suppresses, perhaps even more than the limitation of the speed of light, is
incompatibility of a world's biochemistry with another's life forms. The hard SF
writer has some obligation to account for surmounting this obstacle.
Engineering, even if it does not "terraform'' the planet, can equip prospective
colonists mechanically with spacesuits or living quarters. Bioengineering may
even be able to tailor colonists genetically to suit a world as suggested by
Blish in The Seedling Stars and Le Guin in her Hainish Cycle of SF
narratives.

Given a sun, a body in orbit, and an active chemistry, the writer needs life
forms as well, even for a colony with an artificial support system. It
complicates the model-making process, but biology also has rules worth
observing—or imposing. In explicitly fictional constructs, we should not be
surprised if biological needs determine the design of the world and its
situation in space. At a step further back, of course, story-telling needs may
dictate the choice of biological forms. In theory, however, the hard SF writer
may simply start with cosmological invention, and let each step determine the
next, as Clement and Forward have claimed to do on occasion.

Whichever the sequence of composition, physics and chemistry play a role in
determining biology. A life form needs structure and support, and some means of
sensing its environment. For it to survive and prosper, the functions it
performs demand an optimum size. To move, it needs organs of locomotion large
and strong enough to move its mass. Increased mental powers seem to require an
ability to communicate and to manipulate elements in the environment. Its senses
will be consistent with those functions and its environment. Means of
communication will also be affected by its environment and the material of which
it is composed. On Earth alone, life forms from dinosaurs to ants have found
millions of solutions for these problems which worked for as long as the species
lasted. These all have material bases and constraints.

Beyond physics and chemistry, biology has its own "emergent qualities.'' Life
forms need an energy source, usually the nearest star, even if they use it only
indirectly, i.e., living off stellar energy stored in a planet's molten core.
Carbon, hydrogen, and oxygen, aided by heat, predominate in Earth's life forms,
but life based on other chemical processes is conceivable. See, for example,
Asimov's The Gods Themselves, Clarke's "Out of the Sun,'' Clement's
The Nitrogen Fix, Niven's "The Green Marauder,'' and Stanley G. Weinbaum's
``A Martian Odyssey.''

The ability to move or at least grow means being capable of converting matter
and energy into tissue. This restriction applies even to a life form of
crystalline substance, for which expansion is the only means of growth, as in
Benford and Eklund's If the Stars Are Gods. For these processes to work,
physics and chemistry must permit ingestion, fuel consumption, and excretion. At
the microscopic level, life forms "recognize'' complex hydro-carbons by their
chemical shape, a talent subject to error which can be exploited by invaders,
from drugs to viruses. According to our definition of life forms, they exhibit
sensitivity to their environment and some ``decision-making'' capacity. Aliens
interesting for fiction usually have other mental abilities, too. Brain
functions in our experience require a substantial network of quickly functioning
cells, even if they are not biological in origin. Even before the coming of
computers, SF writers from Murray Leinster to Arthur Clarke speculated about
electronic and inorganic brains. Analogies from computer science now crop up in
discussions of human brains; using cybernetic models, we now find life forms and
computers share electrical charges and switching capacity, if not chemical
transmitters. SF writers from Stapledon to Theodore Sturgeon also have extended
network functions to overcome the isolation of separate brains (analogous to
cells in this context). The number and size of these networks vary, as does the
degree of voluntary participation, though the material basis is largely
sidestepped.

The most characteristically "emergent'' feature of life forms we know is the
struggle for survival. Lacking mentation we can detect, inorganic matter moves
and erodes involuntarily, although at least one Hal Clement story posits
volition to underground pools of petroleum. With organic matter, volition is a
familiar story. Given a finite economy, species compete for survival, and those
that breed before dying bequeath the challenge to a new generation. Species
which fail that test become extinct, and the number of extinct species far
outnumbers those present at any one time. Natural selection is neither gentle
nor relenting to species too slow to adapt. Life forms struggle to survive as
individuals and as species, neither struggle being ultimately winnable. The
chief means of biological survival are finding a niche, reproduction, stability,
and flexibility.

Plants and animals do not come into existence, let alone maintain it, without
raw materials, be those water and sunlight, symbiotic partners, prey (vegetable
or animal), or a combination of these. Plants and animals that serve as prey
must be fast, smart, tough, or inaccessible, to survive predators long enough to
reproduce their kind. If no offspring survive to reproduce themselves, the
species dies out, and with it every individual.

Niches are not permanent, either; floods, fires, climate shifts and
overpopulation can turn a hospitable niche into a deadly trap. "Alien invaders''
(including humans) also change the balance drastically. Even winning the battle
of survival is at best temporary; living things decay, generally at a faster
rate than the inorganic world erodes, leaving only progeny behind to cope in the
next generation. To survive as species, given this rapid decay, life forms
develop strategies to make copies of themselves. The one planet where we have
observed life reveals a profusion of reproductive strategies, from fission to
fusion to sexual breeding, physically interpenetrating or at a distance.

New generations yielded by reproduction must resemble the old ones in most
particulars, if they are to take advantage of the same or similar survival
patterns. At the "atomic'' level, DNA and RNA ensure this consistency and
continuity, but not exactly. Mutations, hybrids, and other adaptations are
common, but generally less effective than the norm, otherwise they would become
the species form. At higher levels of complexity, other conservative forces
operate. A brain too slow or simple (and perhaps too fast or complex) may
provide a meal. An unstable culture will disintegrate if it is not destroyed
from without. Rigid stability is also counterproductive, given the potential
changes affecting an ecological niche. All the eggs or offspring may be eaten,
plants or people wither from drought.

Besides strategies for waiting out the change, migrating, and building
defenses, nature has others in the germ plasm. Much of the DNA molecule is
apparently "garbage,'' doing little to ensure stability; both there and in
behavior, change can enable species survival—at the price of species
modification.

As the organism interacts with its environment, survival requires both
stability and flexibility. The biological imperative to survive and multiply
conflicts eventually with the limits of the physical universe. The elasticity of
these limits is evident from the success of ants, termites, beavers and humans
in modifying their environment. The limits are finite, however, even if we don't
know where the boundaries lie. Without intelligent intervention, ecological
balance may be calculable; adding the potential for engineering changes the
picture, but there's still a frame.

This interaction between organisms and the natural environment is ecology,
the basic principle of which is not stasis but balance. Without environmental
changes, change in organisms would have no survival value. The changes organisms
go through, seeking an edge, themselves upset the equilibrium. Once evolution
starts—i.e., when life begins—the "natural balance'' is continually in flux. If
it is in the nature of human beings to manipulate their environment, the
difference between natural and artificial virtually vanishes.

This continual change in nature Charles Darwin dramatized as the "struggle
for existence.'' One of his major sources, Thomas Malthus, had recognized the
mathematical nature of the problem, asserting that population, otherwise
unchecked, will be stopped by exhausting its environment. The basic principles
of Darwin's theory—natural selection and species variation—permitted calculation
of the changes in balance. It was not until Gregor Mendel, however, that the
``gene'' was identified as the atomic principle behind the mechanism of
stability and change.

The flexibility of germ plasm has caused Darwinists some difficulty in
dealing with borderline classifications. Distinctions require language, making
the problem partly semantic, like differentiating a cult from a sect, or a weed
from a garden plant. At some point, however, just as old species die out,
variation brings new ones into being. On our world, some of these variations are
induced by other species. We must assume at least the possibility of comparable
engineering projects on other worlds, but the evidence can only be drawn from
human history.

Some symbiotic relationships (e.g., ants and aphids) may suggest forced
breeding by species other than ours. The interventions with which we are most
familiar, however, are wrought by human beings, from breeding domestic plants
and animals to deliberate thinning out and accidentally strengthening pests.
Unanticipated effects are common enough in ``vital engineering'' for fantasy and
SF to find it a fruitful area of biological science. Almost as common as the
monster motif in film is the superman in prose fiction.

Postulating radical changes in human form has been a popular entertainment
since classical times, practiced by poets, prose romancers, and mostly anonymous
travellers. Mary Shelley's Frankenstein is the first story to suggest
even vaguely scientific means and motive for creating (or recreating) human
life, though her minimal science, like most people's in that era, smacks of
alchemy and magic. Intervention in natural biological processes appears in the
proto-SF of Edgar Allan Poe, Nathaniel Hawthorne, Ambrose Bierce, and Fitz-James
O'Brien, culminating in Wells, and continuing to the present. Fiction has
treated three major areas for intervention; in ascending order of difficulty,
these are changes in mechanisms, species, and habitat.

Good at analyzing and producing mechanisms, technological humanity has
developed many ways to extend lifespan and preserve a reasonable facsimile of
"mature powers.'' Eye-glasses, hearing aids, prosthetic devices, metal and
plastic joints, iron lungs, kidney machines, and artificial hearts are some
examples from the arsenal of medical technology. Their potential for fiction is
mainly limited to the medical drama involved, when the technology is first
developed; later they are usually trivial. Anyone relying on artificial aids
could be termed a "cyborg,'' but this term in SF usually evokes a being of mixed
identity, often unsure how much of it is human or machine. Asimov, Alfred
Bester, Philip K. Dick, Damon Knight, and C. L. Moore have written classic
stories on this theme. Increasingly porous interfaces between human and machine
make the question progressively more relevant for humanity as well as for SF.

Transplants and transfusions have caused social problems on Earth for
cultural reasons. Dramatic questions have been raised concerning supply and
demand, as well as prejudice between groups regarding themselves as enemies. The
employment of surrogate mothers has raised the spectre of poor women renting
their wombs. Such "baby farming'' arouses both civil libertarians and religious
moralists, though it largely escaped notice in Clarke's Imperial Earth.

At a sensational level, identity questions arise in a number of areas. The
courts have already decided parental rights over eggs fertilized in vitro.
Cloning, already achieved with less complex life forms, raises identity
problems, as Le Guin speculated in "Nine Lives'' and John Varley in several
narratives. Identity is also at issue in the highly speculative example of brain
exchange, treated satirically in a Thomas Mann novella, "The Transposed Heads''
and a Steve Martin film, The Man With Two Brains. Varley's stories treat
it as a serious medical procedure, while writers in many media have almost taken
for granted the possibility of electronic storage and reproduction of brains
alone, or brains and bodies. SF examples include Algis Budrys' Rogue Moon
and every story involving ``matter transmission,'' which must record the entire
being it transmits.

Discovery of the DNA molecule unleashed other potentials on the world,
including isolation of faulty genes and chromosomes, and the manipulation of the
germ plasm itself. Progress on the "human genome project'' portends not only
medical advances, but also the selection and production of desired
characteristics in offspring, such as strength, intelligence, height, color of
skin, hair, and eyes. This prospect raises the historical spectre of "ethnic
cleansing,'' but it goes further, suggesting possibilities for changes in what
we now think the human race does or should consist of. J.D. Bernal raised that
possibility over 60 years ago in The World, The Flesh, and the Devil;
Pohl's best satirical take on it is the short story, "Day Million.''

In such projects, as in cloning, surrogate motherhood, and artificial wombs,
some feminist science critics see efforts to free man from dependency on woman.
Yet cloning and asexual reproduction raise other issues of gender, too,
theoretically freeing women from childbirth, permitting gender shapeshifting,
and rendering men unnecessary from a biological point of view. These issues have
been raised in SF by Marge Piercy, Joanna Russ, Alice Sheldon, Delany, and
Varley, as well as in the classic depiction of an alien world free of limiting
gender roles, Le Guin's The Left Hand of Darkness.

Before manipulating ourselves radically, of course, numerous writers have
suggested we will meddle with other animals, perhaps developing talking dogs as
in Roger Zelazny's The Dream Master, or chimps designed for dangerous
construction work, as in Heinlein's "Jerry Was a Man.'' Humans have bred other
species for millennia, occasionally crossing the line into new species. The
upper classes in human society traditionally attempt to breed their own
subspecies, via arranged marriages, for example. The "Nobel Prize sperm bank''
makes similar eugenic possibilities available to any woman. Dr. Frankenstein's
revival of cadavers gave way in fiction to Dr. Moreau's "beast-men'' created by
vivisection. The technology is different but the goal comparable for inventors
of "designer genes'' and newly patented organisms. On the horizon, moreover, are
biologically-based computer chips, represented as causing unforeseen but
essentially positive changes in the human race. Paul Preuss is basically
extrapolative in Human Error, Greg Bear transformational in Blood
Music.

Human beings have altered their habitat at least since they discovered fire
and invented tools, with major changes for nature in the Neolithic Revolution,
the invention of cities, and the coming of industrialization. Since the last ice
age, technological developments have enabled the species to expand and multiply.
Such development has made it possible for more people than ever to live longer,
more productive lives. It has had its drawbacks, however, for humans have made
other species extinct, and it now threatens extinction for the human race
itself. SF has chronicled thousands of disasters, from the sober speculation of
George Stewart's Earth Abides to the heated extrapolation of Brunner's
The Sheep Look Up, to paranoid scenarios like Wells' War of the Worlds
and Thomas M. Disch's The Genocides. SF cinema contains an even higher
percentage of catastrophes, though Hollywood's ratio of positive endings is also
higher.

SF writers have imagined ways out of this mess, once termed the World
Macroproblem by the Stanford Research Institute. Some of these involve giving up
the comforts as well as the drawbacks of technological civilization, returning
to the more rustic lifestyles of Leigh Brackett's The Long Tomorrow,
Russell Hoban's Riddley Walker, and Edgar Pangborn's Davy. To
maintain a technological civilization indefinitely, SF narratives often require
life support systems, underground (E. M. Forster's "The Machine Stops,'' Harlan
Ellison's ``A Boy and His Dog''), underwater (Henry Kuttner's Fury,
Delany's ``Driftglass''), or under domes (Evgeny Zamiatin's We, John
Boorman's film Zardoz). Off-Earth, the Moon is a favorite domicile and
other occupied planets are too numerous to mention. Space stations or colonies
have proliferated from the simple extrapolation of Clarke's Islands in the
Sky and Blish's Cities in Flight tetralogy to the elaborate
self-replicating galaxy-wanderers of George Zebrowski's Macrolife.

7. Soft Sciences. Brains, communication, and culture seem to be
inseparable, a three-way chicken-and-egg problem. Two brains in communication
form a miniature sub-culture. Increasing the number of brains in communication
makes cultural manifestations more unifying, simultaneously isolating encultured
groups from each other. Brains and bodily expression are generally presumed to
be material, though the shapes and means may bear little resemblance to those
with which we are familiar, even among the profusion of life forms known on
Earth. Communication and culture require these material attributes, but they
need others, too. Communication demands a development of codes or conventions;
unable to exist without them, culture develops out of and also enforces them.

With culture come social organization and engineering. Both bring new
elements into the game of survival, contributing to and withstanding pressures
of the social as well as the natural environment. Both involve effects of
thinking and communication on the environment, from agriculture and habitat
construction to other innovations already mentioned. Communication inevitably
breeds conflict, and social rules breed transgressions, which turn into crime
and war; war in turn potentially leads to wholesale destruction of a country, an
entire world, or just possibly interstellar alliances of worlds. Attenuated as
they are, the material bases of culture and communication are very real, and the
potential for multiple interactions immense, making a true science of culture
difficult if not impossible. Comparability, control, and measurement become
possible only along statistical lines, a situation not totally inconsistent with
the state of affairs in subnuclear physics.

Still more complicated than biology, let alone physics, the soft sciences
achieve quantitative prediction and control mainly by applying statistical
methods to groups of people. Useful principles can arise out of the soft
sciences, though they are hard to prove or disprove, and subject to rapid
obsolescence in a fast-changing history. Complicated by sheer volume, multiple
levels of interactions, motivation by symbols, and awareness of being observed,
the human sciences are also limited in our society by laws regulating
experimentation, unreliable testimony of witnesses, and a degree of resistance
to the very idea of our being predictable. Their relevance to world-building is
apparent only where intelligent life is involved, but readers of fiction have a
limited interest in any other kind. We have evidence about only one intelligent
species but the known history of its many distinct cultures yields a large
variety of alternatives. Brain science, behaviorism, economics, and sociology,
all relevant to the construction of alien beings, are discussed below in order
of decreasing reliability.

Psycho-biology, psycho-chemistry, and psycho-physics have shown great
progress and even greater promise studying the brain and nervous system as
material objects. Brains of both sick and healthy animals, including humans, can
now be analyzed in detail, practically without disturbing the subject. Speed of
synaptic response can be measured and location of receptors determined. Charted
in detail, effects of both physical and pharmacological stimuli (electrodes and
drugs) can be quantitatively predicted. A legitimate category of biological
(hard) science, brain science is a soft science in terms of how much it can not
do, both legally and physically. In SF, however, less limited versions of brain
science may be postulated and enacted, such as Pohl's "Purchased People''
stories, Niven's "Death by Ecstacy'' and Michael Crichton's Terminal Man.

Partly because adherents claimed too much for it, partly because human
behavior varies so widely, partly because people—even scientists themselves (out
of uniform)—bridle at the idea of reduction to stimulus and response,
behaviorism has a bad name with the public, but it refuses to go away.
Behaviorists treat human behavior like that of other animals, disregarding what
may actually go on in the Black Box we call a brain (like brain scientists, they
avoid the word ``mind''). They hold that human behavior can be explained in
terms of physical constraints and cultural conditioning. Indeed, for simple
operational procedures throughout the world of science, behavioral assumptions
are largely accepted. Cultural conditioning is highly complex, of course, and
this complexity is intensified by interaction with the autonomy claimed by
individuals (including behavioral scienctists). As a result, behaviorism has
never been mathematically predictable over a wide range of analysis, although
its claimed potential enables SF writers to project behavioral assumptions into
imagined worlds, human or alien.

The psychoanalytic theories of Sigmund Freud and his contentious disciples
offer to explain individual behavior via simple principles complexly
interpreted. Freud's background in medical research, scientific aims, and
attempts at objective expression lent his discipline a measure of scientific
standing. Softest of the sciences, more a pseudo-science, it is systematic and
based on close observation, but its findings lack refutability. Partly as
compensation, its adherents sometimes approach religious fervor in their own
behavior. Both theory and therapy, psychoanalysis offers to explain and to cure.
With a cure rate roughly equivalent to that of witch-doctors, however, and a
metapsychology exploded by brain science, it has fragmented into myriad cults
while maintaining some allegiance from literary critics.

The "talking cure'' does mirror how people process inchoate ideas bubbling up
from the unconscious, including writers and critics. More an art than a science,
psychoanalysis offers convenient labels for broad-scale behavior patterns. It
has created a kaleidoscope of metaphoric constructions, such as the unconscious
and its divisions (id and superego), the multiplication and fragmentation of
images, and the repression of uncomfortable memories and bodily urges,
especially those of sex and violence. SF writers making explicit use of
psychoanalysis include Kuttner, Moore, Pohl, and Sturgeon; Le Guin's artistic
allegiance is more to Jung, though intellectually she has claimed to lean toward
Freud. The most prominent Freudian analyst of SF was Dr. Robert Plank.

In the long run, everything can be reduced to economics, as the struggle for
existence by other means. Eventually, stars burn out, even the universe reaches
a steady state, after all the essential but scarce goods of energy have been
spent. The balance of nature is one branch of economics, but usually we reserve
the term for the actions of intelligent beings organizing their material
existence.

At one extreme, only Adam Smith's "invisible hand'' of supply and demand
regulates the pure market economy. Given rational behavior by consumers and
producers, price, service and accessibility determine survival of the fittest
among producers and marketing outlets. The same principle should apply in the
sale of ideas as in that of widgets. Pure laissez-faire economy only
exists in the imagination, however, as nostalgia for communitarian open markets
where everyone knew everyone else or as a set of libertarian principles best
fitted to a society of wolves. Modified market economies do operate in the real
world, and the invisible hand can be represented in a purer state in a work of
fiction, operating in a nearly deterministic way, with obvious advantages for SF
projections. Laissez-faire capitalism shares with Mercantilism the
background of Anderson's "Polesotechnic League'' stories and novels. Heinlein's
The Moon is a Harsh Mistress argues the necessity for a market economy,
while a Libertarian position is represented in his Farnham's Freehold and
J. Neil Schulman's Alongside Night.

Theoretically, one could design controls more efficient than those of the
market for using raw materials, transportation, and personnel, educating or
otherwise inducing consumers to buy what is available to sell. Utopian
fictions may succeed as designed, but utopian communities don't, including
nations that pretend to put "socialist'' principles into practice. Conscious
design and deliberate planning, regardless of idealistic intent, run afoul of
human desires for variety, uniqueness, and status. The conflict between
pragmatic ideals for all and preferences for the individual impassions many a SF
story, not just those with a dystopian theme foregrounded. Beyond Ivan
Yefremov's Andromeda and Ernest Callenbach's Ecotopia, we can cite
Heinlein's Beyond This Horizon and Pohl's The Age of the Pussyfoot.

Economic systems in the real world are much more complicated than either
model. "Capitalist'' countries have safeguards to mitigate cutthroat extremes,
to protect businesses as well as consumers, and to maintain an environment in
which competition is worthwhile. ``Socialist'' countries have ``safeguards'' of
their own, including black markets and competition for status and party favors.
Stories reflecting this complexity express more verisimilitude than either
extreme. Like physical laws, both models set constraints, though it is uncertain
whether these limits are real or simply psychological barriers we can not
imagine going beyond.

The most widespread attempts to apply deterministic principles in economics
are the social dicta associated with Karl Marx and the heirs to his mantle, who
made it a coat of many colors. Like psychoanalysis, Marxism is both theory and
therapy, lacking even Freud's medical discipline or scientific reserve. Marx and
Friedrich Engels attempted scientific analysis, but their expression of it
rarely escaped polemic, since the analysis revealed to them both the need and
means for action. As a cure, Marxism is a disaster, though victims of capitalist
oppression still cling to its often laudable ideals. Various conceptual
formulations of Marx and Engels, moreover, concerning ideological constraints,
historical materialism, class struggle, and mutual interactions between economic
interests and the rest of culture have found their way into the common fund of
knowledge.

Heavily indebted to Smith and Friedrich Hegel, Marxist theory has been
refined by several generations of intellectuals, at variant distances from
revolutionary fervor and party discipline. The mechanistic laws Marxists tried
to construct have been less fortunate, but they still offer potential for
extrapolation. Soviet SF found use for them, not always by choice, but so have
British and American writers, not all of whom were sympathetic to the Marxist
cause. Communitarian futures appear in Aldiss' Enemies of the System and
Benford's Against Infinity, variations on anarchism in Le Guin's The
Dispossessed: An Ambiguous Utopia and Eric Frank Russell's "And Then There
Were None.'' Since SF includes materialist futures alternative to capitalism,
Marxist or Marxian critics of SF are common, the best known being Darko Suvin
and Fredric Jameson.

Statistical evidence often serves as raw material for economic models, but
sociology as a science depends mainly on statistical analysis of group behavior.
Along with economic models, sociology has proposed a profusion of principles for
understanding more or less rational behavior. Sociology does a better job
anticipating many behaviors than leaving it to chance, but even the best models
have a 5-10% error rate. Such models typically involve "controlled'' situations,
large numbers of subjects, and research subjects largely unaware of their
status. At best only snapshots of the moment of interview, opinion samples can
easily be skewed by subjects dissembling. Dissembling is more or less
predictable on controversial issues, but it can also embody contempt for surveys
and surveyors in general. More reliable models are traffic patterns, in
buildings and on highways, though mechanical breakdowns and accidents cramp the
predictive model. Statistically, corporate and national behavior can also be
predicted, or at least designed into an alien world.

Like psychology, sociology has a major split between its experimental and
reflective sides. Experimental sociology is often a handmaid of sales campaigns,
for political candidates as well as commercial products and company reputations;
otherwise, it may only confirm the obvious in a complicated manner. The
reflective branch builds elaborate theories on the basis of available
information, which often wind up as intelligent but biased guesswork, impossible
to disprove. Even where sociology is eminently sensible, it is more
retrospective than predictive. From the standpoint of prediction and control, it
may be less an empirical science than a pseudo-science, but that hardly
incapacitates it for extrapolation. Delany's Triton, Pohl's Jem,
and a number of works each by John Brunner and Mack Reynolds are just a few of
the many SF examples of sociology in action.

From its origin in Saussure's linguistics, structuralism proliferated into
other areas of cultural and literary study. Promising to be the quantum theory
of cultural studies, structuralism seemed a way to quantify observation beyond
the vagaries of surface irregularities. Its major exponent, Claude Levi-Strauss,
extended the model of arbitrary and systematic language into kinship
relationships, table manners, totemism, and other largely unconscious social
contracts. He did not succeed in eliminating the role of the outside observer,
however. Rather he imposed a set of arbitrary values into the analysis, such
that his own interpretations often defied replication by others.

In literary studies, structuralism quickly fragmented into numerous analyses
based on virtually any perceptible analogy to structure(s) of language. Language
may be based in arbitrary distinctions, but literary use of language is a highly
self-conscious use of verbal and social codes and conventions. This reflexive
self-analysis may have made the disintegration of structuralism inevitable,
leading to deconstruction and other post-structuralist positions. The most
prominent SF writer and critic overtly associated with such concerns is Samuel
R. Delany, but readings have recently emerged of Dick, Gibson, Lem, and the
borderline SF of Italo Calvino, in which post-structuralism, postmodernism, and
"chaos theory'' seem interwoven.

Psychoanalysis, dialectical materialism, and structuralism may technically be
pseudo-sciences, but they have enough cultural respectability to escape that
definitive judgment. Even less science or inertia supports certain other
"disciplines.'' Just a gleam in Asimov's eye when he began his `"Foundation''
series, psycho-history may be an unconscious mirroring of Marxism, as Charles
Elkins contends. It is also a more market-oriented attempt to treat social
history as statistically predictable on a large scale. For Americans leery of
Marx, it can provide a model, largely uncredited, for forecasts of human
development, both on and off Earth, building up at one point what Donald A.
Wollheim called a consensus ``cosmogony'' for the field. The best known is
Heinlein's "Future History'' but Cherryh, Le Guin, Niven, Pournelle, even and "Cordwainer
Smith'' have adopted their own versions for narratives set in a stable
historical context.

8. Collaborative Efforts. Each story set on an alien world uses
scientific principles and techniques to build up a picture of that world.
Writers of hard SF make a virtue of this necessity, stressing it in essays based
in their own writings. Interested mainly in story-telling, Poul Anderson has
created in his fiction many alien worlds and relations with alien species, in
which human protagonists are involved. He has also written non-fiction about
making human-habitable worlds convincing. Clement was probably the first hard SF
writer to detail in an essay, later an afterword to Mission of Gravity,
its scientific extrapolations. He has since written about how both alien worlds
and alien life forms can be developed in the imagination from scientific
principles, and has carried out these techniques in a dozen novels and several
dozen short stories. Clarke and Benford have also written non-fiction in support
of their fiction. A great propagandist for space travel and the conceptual
inventor of ``stationary'' communication satellites, Clarke wrote fiction and
essays on parallel tracks. Benford's non-technical non-fiction tends to hone in
on SF ideals, with obvious references to his own practice.

Perhaps the most extreme exponent of science for its own sake in SF is Robert
Forward of Hughes Laboratories, whose research reports on space drives,
anti-gravity, and other "far-out''' science have been made readily available to
SF writers and critics over the years. Each of his novels published in the 1980s
takes place on a world different enough from Earth that he has to rely as a
guide for what could happen on the scientific principles according to which the
basic situation could exist. They illustrate the point he made at the 1983 Eaton
Conference on hard SF: when faced with a story-telling decision, he sometimes
"lets the science write the story.'' The physics and chemistry of the situation
themselves make characters' behavior inevitable or at least probable.

World-creation is an act of tremendous arrogance, for one writer or even a
team of savants. The reason is not religious scruples but the need for knowledge
in so many fields of science to do the job well. Even when it is done well, the
accomplishment is only temporary. The project will eventually "date,'' either
because its hypotheticals have come true or because some new discovery or
historical event cancels out its assumptions. The complexity of the task has
been recognized openly more of late than in earlier SF, which often has a
slapdash quality. Writers today acknowledge and follow more scientific sources
or openly pool various kinds and levels of expertise.

Such informal collaboration has gone on undercover for generations, but some
of it now surfaces publicly. A community college in San Jose, California, hosts
an annual conference at which scientists, writers and readers build and act out
alien contact scenarios. An East Coast scientist regularly advertises in
specialty publications his availability as a paid consultant helping design
alien worlds. Scientists, many without SF affiliation, are credited in footnotes
and afterwords, even in novels by established SF writers like Clarke and Preuss.
Such credits have long been the practice in SF feature films from Things to
Come (Wells, 1936) to Destination: Moon (Heinlein, 1950) to 2001:
A Space Odyssey (Clarke, 1968), all made with advice from numerous
scientists. For its setting and cultural behavior, even an unscientific a
recreation of prehistory like The Clan of the Cave Bear (1986) had as
technical advisor primate specialist Desmond Morris, also employed on 2001.

Two recent literary instances merit special mention. Supplements circulated
with advance copies of Helliconia Spring (1982) by Brian W. Aldiss made
explicit his indebtedness to members of the scientific community. Two things
make this example stand out. No scientist himself, Aldiss enlisted a team of
scientific advisors to aid and correct him in creating the alien world on which
his trilogy was set. Moreover, it was apparent that his publisher thought making
this news public was good advertising for an ambitious set of novels by an
author not previously associated with hard SF.

In recent years, several shared-world anthology series have been assembled.
Innocently proposed by the French critic and novelist Michel Butor, something
similar was roundly attacked by SF writers and critics in the Sixties because of
its dangers for higher concepts of art as well as for scientific ingenuity.
Actually pioneered in "triplets'' of novellas published by Twayne in the 1950s,
this concept is regularly used in the Star Trek universe and standard in
virtually every film and television series. With the basic situation already
worked out in the context of scientific constraints, each author can work
changes on it, even affecting stories written by others. In microcosm, this is
not unlike the fictional galaxy or universe SF writers have shared in a dialogue
at least since the 1920s. It even has the beginnings of an artistic defense in
Delany's argument for sequels in The American Shore: an invented world
has more potential than an author can use up in any single narrative.

One notable example of such scientific and science-fictional teamwork is
Medea's World, an anthology edited by Harlan Ellison, who is even less
scientifically oriented than Aldiss. Derived from a Continuing Education Seminar
at the University of California, Los Angeles, this book includes both stories
set upon a consensus alien world developed during the course of study, and
essays helping to set it up and explain it.

9. Extrapolating Historical Processes. Historical extrapolation is
already implicated in world-building. Abstractly, each scientific prediction is
a forecast, but we usually call "historical'' actions taken by human beings not
bound to a traditional cyclical conception of time. Extraterrestrial beings may
have a history, but their actions are part of our creation of their world as in
Blish's A Case of Conscience or the Niven and Pournelle A Mote in
God's Eye. Whatever the human allegory present, invoking the alien has a
distancing effect. About their history we can be relatively neutral, if they do
not threaten our survival. Regardless of which are the interlopers, moreover,
the story will say something about our present precarious toehold in the
universe or on our home world.

In stories explicitly involving Earth in the next century or so, a key
component is the extrapolation of ongoing historical processes. While the
fictional elements of world-creation can usually take for granted the physical
elements of world-creation, interaction between homo sapiens and its
planetary environment is almost always significant. Unlike the extrapolation of
scientific processes, that of historical processes seldom takes a convincing
pose of neutral objectivity. Whether the human race has a future, and what kind
it will be, is of vital interest to both writers and readers of SF. It is
something over which there are profound disagreements as well. The future in
American (and Soviet) SF dominant through the 1950s usually assumed widespread
technological expansion. At some level, writers may have seen technological
expansion more as a threat than a promise, as Barry Malzberg argues in
Engines of the Night. Itself a creature of an age of science, however, the
corporate entity of SF has a vested interest in technological innovation and
relatively free scientific inquiry.

Forecasters deal in predictions of a sort, but they have virtually no chance
to control the situation under study, or even to isolate it. What they study is
not replicable, since historical circumstances are never identical. While their
forecasts may come true, realization of a single prediction does not validate
the techniques or make a prophet reliable. Less a science than an art,
forecasting has degrees of validity and plausibility, invaluable for writers of
SF. It also has a variety of applications, in the hard sciences, soft sciences,
and fiction writing.

Forecasting is not prophecy; it does not read palms, tea leaves, the stars,
auguries of birds, or entrails of animals. Forecasters make no claims of
infallibility. A human exercise in anticipating the disposition of the material
universe by both human and environmental forces, forecasting deals in estimates
of probability. Among its verbal outcomes are predictions, projections,
and scenarios, all of them limited in scope, assumptions, and degrees of
certainty.

Predictions focus on very narrow segments of activity, closely limited
in context. Astronomical predictions are pretty sure bets, and weather
forecasting is more accurate than it gets credit for being. Predictions
involving human behavior are more problematic. The record of technological
forecasting is not bad, and economic and demographic predictions provide moving
targets, while market research best functions as self-fulfilling prophecy. Often
wrong, and surrounded by fuzzy borders even when they're right, predictions at
least are definite about something.

Projections are more broadly conceived, generally in the plural, and
indefinite to a fault. Even if certain conditions hold true, and barring
catastrophe, the expert consensus usually suggests multiple foreseeable outcomes
of a present combination of factors. ``Alternative'' futures describe a range of
possibilities and probabilities, extended from analyses of intersecting and
contradictory trends. Projections may be couched in mathematical terms, but
equations can not encompass all the myriad decisions and exceptions that
determine real futures.

More imaginatively realized, scenarios are not just numbers on a
graph. If not minimally dramatized, a scenario is at least depicted as involving
people, like an architectural model. It shares with predictions a narrow focus.
A scenario is also likely to be more speculative than a projection. If the term
is borrowed from cinema, the activity is familiar in fictional treatments of
future possibilities (utopia, dystopia, and SF).

Reputable forecasters phrase their pronouncements in restrained language.
They specify as much as possible their operating assumptions; if the underlying
assumptions are wrong, the forecast may be worthless. Forecasters typically
underline their forecasts' relationship to context and offer alternative
scenarios. They condition their degree of certainty about an event's occurrence
and when to anticipate it. They also sometimes objectify numerically the
probability of their forecasts' coming true. Inexact as forecasting is, it has
its values, in business, government, and fiction for anticipating the expected
and the surprising.

Even in ancient Babylon, where astronomers read their nation's future in the
stars, forecasting had many applications, but its track record is always spotty.
Then as now, farmers wanted reassurance about the weather, business about the
economic climate, rulers about their term of office. Of today's wide variety of
forecasts, only celestial mechanics is fully reliable. Paradoxically, however,
as forecasting gets less reliable from meteorology to social psychology, our
desire for guidance in facing the future becomes greater, prompting us virtually
to feast on shadows. This gap leaves SF writers a lot of free play in areas that
matter a great deal both to them and to their readers.

The most reliable predictions are in the hard sciences, out of which
fictional world-creation proceeds. Eclipses are safe to predict, as are
"sunrise'' and "sunset,'' even in cloudy weather. Tidal ebb and flow are
consistent, meteor showers periodic. Even sunspots are cyclic, though not all
flareups are predicted. Among physical phenomena, over which human actions have
no sway, the decay of radioactive substances is virtually invariable. Scientists
are only starting to offer rough predictions, however, of seismic activity and
vulcanism. Where human contributions are variable, as in the depletion of the
atmosphere's ozone layer and the phenomena of global warming, we can sensibly
project only a range of probabilities.

The principles of meteorology are so well-established and systematic that its
components can be reduced to mathematics. Observation stations around the world
are supplemented by satellite snapshots, of visual phenomena, humidity, air
pressure, air and sea temperatures, and wind velocity. The general patterns of
movement induced by the Earth's spin and by temperature gradients between the
poles and the equator are well-known. So are the differential effects on weather
patterns of passing over land and sea, mountain and desert, country and city.
Yet for a physical science, its predictions are not as reliable or precise as
everyone wants.

Generally speaking, weather predictions are most reliable in a middle range.
If rain is falling 10 miles west of you with the winds moving east, expect
precipitation soon in your vicinity. One-day predictions for a larger
geographical region are less precise. Five-day prediction is risky, one for six
months to a year chancier still, but much less precision is expected. At either
extreme of scope, the picture becomes fuzzier. Climate change over a long period
and a large area (e.g., the world) is a subject of speculation, but seldom of
certainty. Micro-climates, centering on tall buildings and topographical
anomalies, can defy the experts. Part of the imprecision may stem from
incomplete modelling techniques. Computer models are no better than the
information fed them and the assumptions built into their programs. On both
counts there are factors not fully understood.

Precise observations are not feasible for every square inch of the globe, and
historical records are woefully inadequate, reconstructed from such evidence as
tree rings and sedimentary beds, over time-periods virtually inconsequential in
the history of the planet. For eons longer than the outside estimate of the
human race's three million years, Earth was too hot or cold for human survival,
let alone civilization. Even in historical times, the temperate zones have known
periods uncomfortably warm and chilly, but the cycles and causes are not well
understood.

Meteorologists deal with an interdependent global system, in which there are
puzzling instabilities. The jetstream over North America does not always stay in
its typical range of latitudes, for example. Pronounced and prolonged upwellings
of warm water like El Ni˝o in the central Pacific are unpredictable. Pockets
where the ozone layer has been compromised by human waste products presumably
have or will have an effect on the whole system. Even the planned shutdown in
production of chlorofluorocarbons will yield no noticeable improvement in the
depletion rate for 15-20 years, as residual chemicals waft their way up. Since
the overall weather system is a continuous process with no apparent beginning or
end, simple cause-and-effect thinking is inadequate.

The other major problem in producing satisfactory weather predictions is
customer demand. Hurricane and typhoon watches are generally but not universally
successful in warning people of needed evacuation measures, because so much
instrumentation and attention is directed on a relatively small pocket of
weather. Tornados are smaller and considerably more sudden; forecasters can only
project warnings of probable tornado activity, leaving individuals to safeguard
themselves at the signs of imminent disaster. The temperature range in which
humans can survive unaided is small in cosmic terms, the comfort range smaller
still. Weather forecasters actually give good probabilities for precipitation
and temperature ranges over a moderate geographical range. The average person
often wants to know how to dress for the day or night in specific geographical
areas, and that range of precision just isn't available.

If weather forecasting is problematic, where the components are inanimate and
basically understood, much chancier are the varieties of social forecasting,
where human beings are involved and the determining mechanisms are broadly
outlined at best. Technological, economic, and sociological forecasting methods
are the best tools available so far. They at least give planners and fiction
writers something to shoot for. Of the areas considered, technological
forecasting has the best track record. It also has the most sophisticated tools
and the narrowest scope of study. Technological forecasters routinely predict
not only whether something will be developed, but also when, sometimes within
narrow parameters.

In the short range, engineering developments can be found on drawing boards
and their exploitation anticipated along a ``development curve.'' A typical
15-year period for new technology lasts from inception to mass availability,
taking into account competing solutions to a problem. Over a longer range,
forecasters consider more universal long-term demands, based on the potential of
existing technology, priority direction of resources, and pure guesswork. A
private firm or government agency trying to develop a technology has its own
timetable, affected not only by problems resisting engineering solutions, but
also by organization and financial problems often unrelated to technological
feasibility. Cost-overruns are not infrequent, especially if the federal
government foots the bill.

Technological forecasting outside one's immediate project is more
problematic. It largely depends on a consensus of experts in a discipline.
Researchers outside a project have limited access to proprietary information,
via conferences, periodicals, telephone calls, E-mail, and even industrial
espionage. Surveys like the DELPHI method, however, ask general questions about
the likelihood of a certain problem being solved. Recycling a first round of
answers through the same experts produces a high degree of probability, even if
many participants are hesitant to reveal their own activity. The DELPHI method
is particularly effective for ongoing or anticipated activities where the
capacities of the market and the technology are established, and the skill of
the questioners is highly competent. Even then, technological feasibility may
not suffice, as picture-phones demonstrate.

Forecasts for ``breakthrough'' technologies or ``wild card'' activities are
less reliable, almost by definition. Forecasters sometimes reach beyond the
realms of their expertise as well. Some technological advances, for example, are
widely anticipated with no hard data available on the solution of the problem.
They include controlled nuclear fusion, safe hydrogen fuel, cryonic brain
preservation, space drives more economical than rockets and/or capable of a
significant fraction of the speed of light, and space elevators (continuous loop
transporters between earth and a body in synchronous orbit around the equator),
not to mention cures for cancer and the common cold.

Technological advances such as these are a staple of SF, vying with alien
contact for central position in the genre. The SF writer lacks the engineer's
responsibility for making something work, or the marketer's problem of getting
people to buy it at a price that makes a profit. The writer's obligation is to
make plausible both the science and the demand behind the advance. Some stories
basically stop there, yet the writer also has the option of treating the
workings of an advance as a Black Box. A story with social relevance and
resonance will also suggest possible effects of an advance, especially
unintended consequences. As an entertainer, moreover, the writer has the
responsibility of finding a striking or dramatic way to incorporate the advance
into a narrative.

"Economic man'' is assumed to make decisions in his self-interest, rationally
analyzed. Less reliable than technological forecasting, the economic variety is
more suggestive for dramatic conflict, despite its reputation as the "dismal
science,'' an adjunct to accounting. This model is adequate to many spheres of
action, and extendable to the greater economy of time and effort expended, not
just money. Economic forecasting is notoriously unreliable, however, even at the
macro level. Governments, businesses, even individuals depend on economic
forecasts for management, budgeting, and planning (each in itself a kind of
forecasting). Soviet-bloc planners are prime examples of the impossibility of
accounting for all relevant factors, including human obstinacy, and planning
effectively for all contingencies. A market economy also involves a variation of
the Hawthorne Effect. Knowledgeable people in positions of power can react
swiftly to forecasts and actions by both government and business, slowing or
even reversing their effects. Ordinary consumers can have a similar effect
acting in concert, acting strictly for themselves, with no premeditated social
effect; fear of a shortage can lead to hoarding, which makes the shortage
certain.

If technological forecasts succeed within certain limits, and economics
reliably measures desire, sociological forecasting is still in its infancy,
seeking a purpose as well as a sound methodology. For fiction, this leaves a lot
of room for arbitrary or thematically-linked invention, however constrained by
natural law, technology, and economics. Examples of applied sociology include
demographics (population statistics), market research (politics and products),
and fashions (including fads).

Human population growth must have limits; it can not be the only component of
Earth's biomass, let alone the planet. Nobody knows, however, which constraints
will kick in when, if growth is not slowed voluntarily. With modern medicine
greatly reducing the brake of infant mortality, voluntary birth control
(correlated with higher material living standards) is the only means of
compensation we regard as humane. Other killers persist, however, and large
families are the norm in many parts of the world, for rational economic reasons
as well as traditional religious teachings. Factoring in war, pestilence, and
birth control, demographers typically work with low, medium, and high estimates
over short, medium, and long terms. Projections are largely guesswork, with
breeding decisions in the hands of individuals, but business, religious, and
governmental policies can have significant effects. Besides plague, war, and
programmatic reductions in fertility, SF writers like Aldiss, Blish, Brunner,
Pohl and Kornbluth, and Robert Silverberg, have considered varied effects of
continued growth.

Applied demographics, using such estimates for financial gain, attempts finer
gradations of cultural and economic difference. While education has been
notoriously fallible in predicting future needs, some business ventures have
been more successful. Researching what people buy, wear, eat, and watch and how
they vote has become a major industry, with computerized inventory records and
market profiles tracking behavior by postal zones, voting districts, even city
blocks. Forecasting future behavior has limited scientific validity, however,
based as it is largely on straight-line extrapolations, often static or
inertial.

Demographers may turn up solid economic data based on what people do, but
pollsters can only measure what people are willing to say, at the time they are
being polled. Rarely disinterested, such research affects behavior primarily if
followed by immediate efforts to reinforce or rechannel the opinions revealed,
something competitors are also attempting from a different angle.

At the level of culture, history and sociology chronicle changes in taste and
fashion, but cannot predict them with any accuracy. To create self-fulfilling
prophecies, the fashion industry uses enforcement mechanisms like the cabals
that decide the colors to be marketed each year, but none is foolproof. Fashion
also has material causes, including availability of textiles or composites. Over
time, Clothes even make broad symbolic statements that no individual may
actually have planned. Black suits and stovepipe hats embodied the grimy
industrial cities of the 19th century; white gloves and high heels suggest a
woman of leisure. Sociologists have also found fashion cycles keyed to such
indices as gender ratio, economic conditions, war and peace. Rising and falling
necklines and hemlines may adhere to regular periods, but they are only part of
a style, and not everyone follows the dictates of haute couture.

Fads generally have a shorter and largely predictable lifetime, the
inevitable end of which businesses often fail to anticipate. Forecasters can
offer generalizations about typical cycles; some, like Faith Popcorn, even work
at a level comparable to astrology in offering guidance to business. SF writers
like Brunner, Delany, and Spinrad also invent changes in fads and fashions, new
slang and customs as well as major clothing styles and individual fashion
statements. Subject only to constraints of contemporary plausibility, such
inventions are entertaining but usually date quickly. They rarely succeed as
prediction.

Forecasting is not strictly a scientific activity. The factors to be
considered are many, few of them simple, and chief among them is the
unpredictability of the isolated individual. Only on a wider scale and a longer
time- frame, subordinating individuals to statistical analysis, can forecasting
hope to reach a high degree of scientific reliability. Even then,
interpretations will differ. A mixture of possibility and desire, social
forecasting is primarily an affair of words and ideas, i.e., a literary
activity.

10. Literary Forecasting. In addition to having tools of hard and soft
science at their disposal, with some pretense to objectivity, SF writers have a
major interest in subjective issues. Human desires, largely unsatisfied, are
constants in their trade, and powerful counters in SF with its emphasis on
potential. A wide variety of characters will share some of these desires, with
consequences that are sometimes foreseeable. The behavior of individuals
sometimes can be forecast from character and situation. On the level of
motivation, however, the SF writer must keep in the forefront goals a writer of
contemporary realism can take for granted as shared background. Primary factors
shaping the world-views of characters include long-term human desires,
short-term economic preferences, and the effects of both on the environment and
human survival within it.

Inventions in history as well as in SF are largely efforts to secure things
or situations people wanted long before modern technological society, as Kurt
Marek points out. Cultural practices, stories and myths illustrate the need of
homo sapiens for food and shelter, transportation and communication,
medicine, social organization, understanding, even disinterested knowledge. SF,
engineering, and science often reflect desires enshrined in prehistoric myth and
material practices of both past and present, as well as technologies seen today
as capable of realization.

Food and shelter are primary needs, which exfoliate into myriad practices,
distinguishing cultures as civilized in their own eyes in contrast to others
whom they see as barbarian. Some SF (Clarke's comes to mind) transforms
agriculture by eliminating the need for human labor, or replacing organic forms
via chemical transformations. This is not to ignore innovations like hydroponics
and "green revolution'' hybrids already capable of feeding far larger multitudes
than those who go hungry today for lack of distribution. Domestication of
animals in SF extends to increasing their intelligence and capability, typically
to handle menial occupations, and even to enslaving intelligent species,
including ourselves.

SF's architectural imagination may be revealed less by its writers than by
the ``ultra-modern'' visions displayed by its illustrators since the 1920s. On
the covers of magazines and inside as well, graceful buildings soar into the
sky, connected by fluid-appearing bridges and causeways. The urban complex
becomes a "machine for living,'' consistent with the visions of Le Corbusier and
Frank Lloyd Wright, and echoed in real buildings today, perhaps especially
hotels (SF is in some ways a literature for tourists). Films often use a heavier
hand to draw our architectural future, from the expressionistic horror of
Metropolis and the defiant confidence of Things to Come to the
miles-long computer of Forbidden Planet and the somber anarchy of
Bladerunner.

To survive and to accomplish what a society values requires social
organization. The six basic types defined by Aristotle were monarchy,
aristocracy, and polity, and their ``perversions'' tyranny, oligarchy, and
democracy. The intervening centuries have worked many variations on these, and
social organization in the modern world is both aided and complicated by
technologies. New means of production and distribution, communication and
transport, inevitably affect it. Of primary importance are information access
and power relations, not to mention mechanisms of fiscal credit. Innovations in
these areas will impact and reflect changes in living quarters, health care,
child-rearing and education. Add to that the potential for integrating into
society various new species (robots, upgraded animals, other biological
creations, even aliens) and this vast canvas becomes even more complicated.

The emergence of individual traits seems universal among humans, but its
genetic base is given expression according to highly determining social
constraints. Even what one understands as the "self'' comes from socially
approved means of investigation and communication. Social sources determine what
matters to us about our relationships with others, with our immediate
environment, and with biology and physics. Writers typically find
self-understanding important for characters and/or readers, but the SF writer
also sees it as part of an alternate universe the fiction constructs.

Art, religion, philosophy, and science are both formal disciplines and
informal activities through which we pursue meaning and self-understanding. They
are not mutually exclusive or all-encompassing, however, since magic and
psychology, for example, may be classified under any of them or all four.
Everyone has a personal investment, however unconscious, in a society's image of
the race and its place in the universe. Even a willingness to pursue knowledge
without regard for where the search leads has a personal element. Yet
practitioners of these disciplines sometimes become so deeply involved in the
quest for truth as to seem disinterested.

These long-term desires are most often made real through relatively
short-term economic decisions. It is also safe to assume that some decisions are
based almost strictly on short-term economic preferences. These include survival
needs in times of scarcity as well as questions of which product if any to buy
in times of affluence. If the two interests do not coincide, the writer can play
off the ``rational man'' of economics against irrational preferences based on
deep-seated drives. Choices available to the rational self come from an
irrational menu. Driven by long-term or even universal goals, pragmatically
making short-term decisions, characters and whole societies in SF often live and
cope with unintended effects of their choices (or those of their peers and
predecessors).

Individual economic decisions may be rational or irrational, calculable or
incalculable. The drama, in both real life and fiction, lies not in the
mathematics of budgeting, but in the means by which agents and agencies try to
bring the world and their budgets into conformity. In the broader scale of
economics lies the most personal and perhaps the scarcest commodity of all, the
time allotted to one's life, giving rise to speculation about the degree to
which one can plan it, and even extend it.

Cultures as well as species take self-preservation into account, rearing and
educating their young, regulating sex and marriage, organizing their mutual
interactions so as to insure the survival of their "way of life.'' Like
corporations, government and other bureaucracies may seem virtually immortal on
the time scale of an individual's life. Yet governments and forms of government
fall, businesses fail, and corporate culture continually alters as participants
change places and go through transitions as individuals. Cultures also differ in
terms of how much they encourage individuals to melt into or oppose corporate
existence, or even to recognize the possibility of divergence. Utopian and
dystopian fictions are built on forecasting such convergence or divergence of
interests.

Individual planning is always subject to corporate behavior, in terms of
one's role in a tribe or a company, and restrictions imposed by laws,
regulations, mores, and leaders flexing their will. Tying one's future to that
of the tribe seems far more common in human experience than keeping one's
distance. Individual planning for retirement, economic security, and career
advancement, as well as marriage and children, is especially encouraged in
today's macro-culture misnamed "the West.'' While such planning is constrained
by physics and biology, the resources of Western science and technology are also
directed toward overcoming or at least relaxing those limits.

Though opinions differ about quality of life in industrial society, modern
medical science has clearly increased the average human life-span. Reductions of
death in infancy and surgery comprise a major portion of that increase, while
the biggest headlines and headaches come from surgical and chemical advances
extending the lives of the elderly and the infirm. SF stories imagine future
medical facilities with mechanical and psychic healers able to mend breaks and
ruptures of every kind, even to suspend animation until more specialized
facilities can restore life itself. The ultimate goal in this direction is
immortality, or at least greatly extended longevity, without debility.

Avenues with fictional promise in this perhaps chimerical quest include
cryonics, cloning, and electronic transfer of personality. Parallelling ancient
practices of mummification, cryonics is a delaying action, freezing the body
immediately after death. Suspended animation with appropriate drugs might be
preferable but earlier intervention with freezing is treated as murder. If
cloning is carried out with human cells, it promises only cellular immortality,
without a mechanism of brain or memory transplant. Individuals then would not
have to be limited to the same body at a different biological age, but could
change appearance including gender at will. Whether or not organic brain
transplants work out, immortalists hope for electronic recording and
transference of partial or whole personalities (Gregory Benford's Tides of
Light and Great Sky River), or bodiless electronic being (Frederik
Pohl's Heechee tetralogy).

SF offers a bewildering range of tools with which to forecast characters'
behavior, or invent new behaviors, suggesting that character is only a
complicated automated mechanism. But behavioral forecasting is by no means
limited to SF. Even without the benefit of scientific vision, or modern science
in particular, literary conventions alone require a certain amount of
forecasting in order for plot and character to interact.

Plot is what characters do, and characters are the agents that carry out the
plot. In a string of events causally united, character motivation must be
established in terms of tendencies and potential. Characters are thin in fairy
tale and romance and their behavior is almost completely predictable. The
realistic novel or short story usually overlays such conventions with more
complicated motivations. Said to be based on real life, such motivations may be
described more precisely as partly based on observations of real life as it was
lived among the Western middle classes in the 18th and 19th centuries. Seen
against that highly constrained and constructed context, these tendencies and
motivations may be legitimately described as plausible. The codes and
conventions of realism are far less dominant in the 20th century, with its
bewildering variety of media, genres, behaviors, attitudes, and techniques.

Characters are not strictly separable from story, but in any story the writer
has to forecast how individuals would behave when subjected to certain
pressures. émile Zola first articulated the deterministic assumptions governing
naturalism. In The Experimental Novel, Zola pushed to extremes the
analysis of people interacting with such pressures, pretending to substitute
dispassionate research and neutral observations for subjective desires and
aesthetic goals. Zola never fully put his ideas into practice in his novels—he
was too good a writer for that—but SF owes much to Zola's conception, or at
least to the 19th century Western scientific climate he expressed. Zola's
"experimental method'' was ready-made for story-tellers lacking an observational
base for how people actually behave in places and times that are only potential.
SF writers following Zola's model can rely on technological forecasting for the
initial impetus, basing character reactions on a variable mix of theory,
history, and arbitrary invention. The first to do so was Zola's contemporary,
Verne, the father of hard SF.

Verne meticulously researched scientific details for neutral presentation,
but his fiction was by no means neutral about what people did with science and
technology. More so than disinterested knowledge, neutral extrapolation is an
oxymoron. Even writers who consciously avoid firing warning shots or rallying
readers around a flag can not avoid utopian or dystopian interpretations of
their work. Most SF writers have strong opinions on what is desirable in the
futures they anticipate. Moreover, a writer need not anticipate, design, or
desire a perfect world in order to write a utopian story. Classic tales of the
'20s and '30s may have described a high-technology future to parade scientific
marvels rather than examine their effects, but the not-so-hidden assumption was
that technology was good for us. Soviet SF, even after the "thaw'' of the
mid-50s, largely toed an ideological line reflecting real-life experience for
few of their readers: already great, socialism was destined to be even better.

Typically, however, people in SF are neither angels nor devils, making
utopian worlds not perfect, but only potentially better. Even B.F. Skinner's
doctrinaire behaviorist utopia, Walden Two, accepts imperfections
inherent in the biological creatures we are. SF generally meets the preference
of readers since Dante's time for Hell over Heaven. Things can go wrong more
ways than right, and complications make stories interesting. The "comic
infernos'' Kingsley Amis found in the 1950s may be especially representative of
American SF of that era, but cautionary tales have always abounded in the genre.

The outright dystopia, perfection inverted, is rare in SF, unlike the
anti-utopia with its resistance to social planning. In history, private
or corporate planning has always served mainly to enrich or protect an elite
class. For those unable to reap its benefits, governmental planning may be the
only defense, even if the rich also get a share. Elites probably could not buy
better propaganda than anti-utopians' depiction of government planning as anti-populistic
and likely to usher in stifling social controls. Yet the danger of too little
planning is equally visible in future-scene stories of war, ecological
catastrophe, and natural disaster.

10. Models are Destiny? The futurologist Frederik W. Polak maintains that
every society is guided in part by the images it projects of its own future. In
SF, forecasting and planning mean determining a future, in the sense of making
it so. Perhaps nowhere is that more visible than in models for a future Earth
and artificial habitats. In the far future on Earth, or after a catastrophe
virtually wipes out technological civilization, a new model is needed. Even with
changes in the astronomical coordinates, many physical conditions will continue.
Artificial habitats are more complicated, involving both world-building and
forecasting. Unlike with an alien planet, writers are not trying to outguess
nature. Space stations and other artificial habitats anticipated for our near
future obviously require technological forecasting, some based on what is on the
drawing boards of several nations. Alien habitats must also be treated as future
engineering projects, since we have no historical experience of many of the
products and processes imagined.

Where human artifacts are concerned, we can start with tried technology,
tested physical principles, and standard assumptions about what human beings
need and want. The further we imagine into the future, however, the more
technological innovations, cross-impacts, and secondary effects may interact.
The result may be something far beyond anything we can do today. It may be
something it is hard to feel we would even want, given our present cultural and
biological configurations. Imagining what aliens would want and how they would
realize it materially follows a similar continuum. The nearer the alien habitat
to what we think we would want, the more it seems constructed for human beings
in costume, as in many SF films and tv shows.

These principles clearly apply to space stations, the most obvious near
future advance into space for the human race. They also apply to settlements on
hostile worlds (i.e., any alien planet) and to any vehicle in which a species
sets out to explore its solar system and beyond. Spaceships take various sizes
and configurations in SF narrative and film, depending on function and motive
power. Writers make vehicles of hollowed-out asteroids, commandeered planets,
and total human fabrications, from space colonies in Earth orbit or visiting
other worlds and star systems, to still larger structures. Niven's Ringworld
postulates a structure surrounding a sun in the plane of the ecliptic;
Orbitsville by Bob Shaw goes him one better, surrounding the sun in all
directions. Ostensibly built by aliens, both are variations on Freeman Dyson's
idea that a Stage Two technological civilization would harness all the energy of
its star. A step further out is the human-built space-time structure in Greg
Bear's Eon, which looks to be both infinite and eternal.

Imagining such artifacts clearly requires extrapolation of the engineering
potential in alternative futures as well as the extension of human scientific
categories and natural laws to the universe outside our immediate vicinity. In
this context, at least, extrapolations of scientific and historical processes
are complementary activities, two ways of modelling the same thing, but
world-building and forecasting coalesce in another sense. Imagining either
alternative futures or alien worlds is a process of extending the empire of
human understanding into unknown time and space. All ``worlds'' of SF are
imagined artifacts, models of how we think things are or could be.

A Partial Secondary
Bibliography for Extrapolation

This list supplements the "hard SF'' secondary bibliography for the
introduction, mainly with works about science and literature cited or otherwise
used in preparing this essay. Everything from the other list should apply here
as well. This list does not document fiction or films cited.

Corbusier, Le [Charles-Edouard Jenneret-Gris]. The Radiant City: Elements
of a Doctrine of Urbanism to be Used as the Basis of Our Machine Age
Civilization. NY: Orion, 1967. [French edition, La Ville radieuse,
1933].

—————, and David Langford. The Third Millennium; A History of the World:
2000-3000 A.D. 1985. London: Paladin 1988. Stanford Research Institute,
Center for the Study of Social Policy. Changing Images of Man. Menlo
Park, CA: Stanford Research Institute, 1974.

Suvin, Darko. Metamorphoses of Science Fiction: On the Poetics and History
of a Literary Genre. New Haven, CT: Yale UP, 1979.

Taylor, Gordon Rattray. The Biological Time Bomb. NY: New American
Library, 1968.

—————. The Doomsday Book: Can the World Survive? Greenwich, CT:
Fawcett, 1971.